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Robert Leff

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101-467: Robert Leff co-founded the computer software distribution company Softsel in 1980, and developed the venture into a $ 5 billion, multi-national computer products distributor now named Merisel. Softsel (originally called Robwin Computing) initially grew out of a distribution company Leff bought from Sierra On-Line co-founder Ken Williams . This article about a United States businessperson

202-461: A 32-bit number. IPv4 is the initial version used on the first generation of the Internet and is still in dominant use. It was designed in 1981 to address up to ≈4.3 billion (10 ) hosts. However, the explosive growth of the Internet has led to IPv4 address exhaustion , which entered its final stage in 2011, when the global IPv4 address allocation pool was exhausted. Because of the growth of

303-515: A 4G network. The limits that users face on accessing information via mobile applications coincide with a broader process of fragmentation of the Internet . Fragmentation restricts access to media content and tends to affect the poorest users the most. Zero-rating , the practice of Internet service providers allowing users free connectivity to access specific content or applications without cost, has offered opportunities to surmount economic hurdles but has also been accused by its critics as creating

404-509: A vulnerability . Software patches are often released to fix identified vulnerabilities, but those that remain unknown ( zero days ) as well as those that have not been patched are still liable for exploitation. Vulnerabilities vary in their ability to be exploited by malicious actors, and the actual risk is dependent on the nature of the vulnerability as well as the value of the surrounding system. Although some vulnerabilities can only be used for denial of service attacks that compromise

505-520: A web application —had become the primary method that companies deliver applications. Software companies aim to deliver a high-quality product on time and under budget. A challenge is that software development effort estimation is often inaccurate. Software development begins by conceiving the project, evaluating its feasibility, analyzing the business requirements, and making a software design . Most software projects speed up their development by reusing or incorporating existing software, either in

606-517: A blog, or building a website involves little initial cost and many cost-free services are available. However, publishing and maintaining large, professional web sites with attractive, diverse and up-to-date information is still a difficult and expensive proposition. Many individuals and some companies and groups use web logs or blogs, which are largely used as easily being able to update online diaries. Some commercial organizations encourage staff to communicate advice in their areas of specialization in

707-457: A change request. Frequently, software is released in an incomplete state when the development team runs out of time or funding. Despite testing and quality assurance , virtually all software contains bugs where the system does not work as intended. Post-release software maintenance is necessary to remediate these bugs when they are found and keep the software working as the environment changes over time. New features are often added after

808-486: A code's correct and efficient behavior, its reusability and portability , or the ease of modification. It is usually more cost-effective to build quality into the product from the beginning rather than try to add it later in the development process. Higher quality code will reduce lifetime cost to both suppliers and customers as it is more reliable and easier to maintain . Software failures in safety-critical systems can be very serious including death. By some estimates,

909-626: A collection of documents (web pages) and other web resources linked by hyperlinks and URLs . In the 1960s, computer scientists began developing systems for time-sharing of computer resources. J. C. R. Licklider proposed the idea of a universal network while working at Bolt Beranek & Newman and, later, leading the Information Processing Techniques Office (IPTO) at the Advanced Research Projects Agency (ARPA) of

1010-593: A designated pool of addresses set aside for each region. The National Telecommunications and Information Administration , an agency of the United States Department of Commerce , had final approval over changes to the DNS root zone until the IANA stewardship transition on 1 October 2016. The Internet Society (ISOC) was founded in 1992 with a mission to "assure the open development, evolution and use of

1111-568: A framework known as the Internet protocol suite (also called TCP/IP , based on the first two components.) This is a suite of protocols that are ordered into a set of four conceptional layers by the scope of their operation, originally documented in RFC   1122 and RFC   1123 . At the top is the application layer , where communication is described in terms of the objects or data structures most appropriate for each application. For example,

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1212-419: A larger market or even sell goods and services entirely online . Business-to-business and financial services on the Internet affect supply chains across entire industries. The Internet has no single centralized governance in either technological implementation or policies for access and usage; each constituent network sets its own policies. The overarching definitions of the two principal name spaces on

1313-443: A legal regime where liability for software products is significantly curtailed compared to other products. Source code is protected by copyright law that vests the owner with the exclusive right to copy the code. The underlying ideas or algorithms are not protected by copyright law, but are often treated as a trade secret and concealed by such methods as non-disclosure agreements . Software copyright has been recognized since

1414-597: A network into two or more networks is called subnetting . Computers that belong to a subnet are addressed with an identical most-significant bit -group in their IP addresses. This results in the logical division of an IP address into two fields, the network number or routing prefix and the rest field or host identifier . The rest field is an identifier for a specific host or network interface. The routing prefix may be expressed in Classless Inter-Domain Routing (CIDR) notation written as

1515-488: A node on a different subnetwork. Routing tables are maintained by manual configuration or automatically by routing protocols . End-nodes typically use a default route that points toward an ISP providing transit, while ISP routers use the Border Gateway Protocol to establish the most efficient routing across the complex connections of the global Internet. The default gateway is the node that serves as

1616-461: A quick web search . Most creative professionals have switched to software-based tools such as computer-aided design , 3D modeling , digital image editing , and computer animation . Almost every complex device is controlled by software. The Internet The Internet (or internet ) is the global system of interconnected computer networks that uses the Internet protocol suite (TCP/IP) to communicate between networks and devices. It

1717-593: A shorthand for internetwork in RFC   675 , and later RFCs repeated this use. Cerf and Kahn credit Louis Pouzin and others with important influences on the resulting TCP/IP design. National PTTs and commercial providers developed the X.25 standard and deployed it on public data networks . Access to the ARPANET was expanded in 1981 when the National Science Foundation (NSF) funded

1818-470: A sign of future growth, 15 sites were connected to the young ARPANET by the end of 1971. These early years were documented in the 1972 film Computer Networks: The Heralds of Resource Sharing . Thereafter, the ARPANET gradually developed into a decentralized communications network, connecting remote centers and military bases in the United States. Other user networks and research networks, such as

1919-495: A significant role in the distribution of software products. The first use of the word software is credited to mathematician John Wilder Tukey in 1958. The first programmable computers, which appeared at the end of the 1940s, were programmed in machine language . Machine language is difficult to debug and not portable across different computers. Initially, hardware resources were more expensive than human resources . As programs became complex, programmer productivity became

2020-458: A specific version of the software, downloaded, and run on hardware belonging to the purchaser. The rise of the Internet and cloud computing enabled a new model, software as a service (SaaS), in which the provider hosts the software (usually built on top of rented infrastructure or platforms ) and provides the use of the software to customers, often in exchange for a subscription fee . By 2023, SaaS products—which are usually delivered via

2121-415: A system's availability, others allow the attacker to inject and run their own code (called malware ), without the user being aware of it. To thwart cyberattacks, all software in the system must be designed to withstand and recover from external attack. Despite efforts to ensure security, a significant fraction of computers are infected with malware. Programming languages are the format in which software

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2222-596: A two-tiered Internet. To address the issues with zero-rating, an alternative model has emerged in the concept of 'equal rating' and is being tested in experiments by Mozilla and Orange in Africa. Equal rating prevents prioritization of one type of content and zero-rates all content up to a specified data cap. In a study published by Chatham House , 15 out of 19 countries researched in Latin America had some kind of hybrid or zero-rated product offered. Some countries in

2323-466: A vast and diverse amount of online information. Compared to printed media, books, encyclopedias and traditional libraries, the World Wide Web has enabled the decentralization of information on a large scale. The Web has enabled individuals and organizations to publish ideas and information to a potentially large audience online at greatly reduced expense and time delay. Publishing a web page,

2424-696: A web browser operates in a client–server application model and exchanges information with the HyperText Transfer Protocol (HTTP) and an application-germane data structure, such as the HyperText Markup Language (HTML). Below this top layer, the transport layer connects applications on different hosts with a logical channel through the network. It provides this service with a variety of possible characteristics, such as ordered, reliable delivery (TCP), and an unreliable datagram service (UDP). Underlying these layers are

2525-581: A wide variety of other Internet software may be installed from app stores . Internet usage by mobile and tablet devices exceeded desktop worldwide for the first time in October 2016. The International Telecommunication Union (ITU) estimated that, by the end of 2017, 48% of individual users regularly connect to the Internet, up from 34% in 2012. Mobile Internet connectivity has played an important role in expanding access in recent years, especially in Asia and

2626-525: Is a network of networks that consists of private , public, academic, business, and government networks of local to global scope, linked by a broad array of electronic, wireless , and optical networking technologies. The Internet carries a vast range of information resources and services, such as the interlinked hypertext documents and applications of the World Wide Web (WWW), electronic mail , telephony , and file sharing . The origins of

2727-547: Is a global network that comprises many voluntarily interconnected autonomous networks. It operates without a central governing body. The technical underpinning and standardization of the core protocols ( IPv4 and IPv6 ) is an activity of the Internet Engineering Task Force (IETF), a non-profit organization of loosely affiliated international participants that anyone may associate with by contributing technical expertise. To maintain interoperability,

2828-407: Is a stub . You can help Misplaced Pages by expanding it . Computer software Software consists of computer programs that instruct the execution of a computer . Software also includes design documents and specifications. The history of software is closely tied to the development of digital computers in the mid-20th century. Early programs were written in the machine language specific to

2929-399: Is a large address block with 2 addresses, having a 32-bit routing prefix. For IPv4, a network may also be characterized by its subnet mask or netmask , which is the bitmask that when applied by a bitwise AND operation to any IP address in the network, yields the routing prefix. Subnet masks are also expressed in dot-decimal notation like an address. For example, 255.255.255.0 is

3030-494: Is necessary to allocate address space efficiently. Subnetting may also enhance routing efficiency or have advantages in network management when subnetworks are administratively controlled by different entities in a larger organization. Subnets may be arranged logically in a hierarchical architecture, partitioning an organization's network address space into a tree-like routing structure. Computers and routers use routing tables in their operating system to direct IP packets to reach

3131-532: Is not directly interoperable by design with IPv4. In essence, it establishes a parallel version of the Internet not directly accessible with IPv4 software. Thus, translation facilities must exist for internetworking or nodes must have duplicate networking software for both networks. Essentially all modern computer operating systems support both versions of the Internet Protocol. Network infrastructure, however, has been lagging in this development. Aside from

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3232-406: Is often accessed through high-performance content delivery networks . The World Wide Web is a global collection of documents , images , multimedia , applications, and other resources, logically interrelated by hyperlinks and referenced with Uniform Resource Identifiers (URIs), which provide a global system of named references. URIs symbolically identify services, web servers , databases, and

3333-453: Is written. Since the 1950s, thousands of different programming languages have been invented; some have been in use for decades, while others have fallen into disuse. Some definitions classify machine code —the exact instructions directly implemented by the hardware—and assembly language —a more human-readable alternative to machine code whose statements can be translated one-to-one into machine code—as programming languages. Programs written in

3434-555: The Oxford English Dictionary found that, based on a study of around 2.5 billion printed and online sources, "Internet" was capitalized in 54% of cases. The terms Internet and World Wide Web are often used interchangeably; it is common to speak of "going on the Internet" when using a web browser to view web pages . However, the World Wide Web , or the Web , is only one of a large number of Internet services,

3535-1050: The American Registry for Internet Numbers (ARIN) for North America , the Asia–Pacific Network Information Centre (APNIC) for Asia and the Pacific region , the Latin American and Caribbean Internet Addresses Registry (LACNIC) for Latin America and the Caribbean region, and the Réseaux IP Européens – Network Coordination Centre (RIPE NCC) for Europe , the Middle East , and Central Asia were delegated to assign IP address blocks and other Internet parameters to local registries, such as Internet service providers , from

3636-984: The Computer Science Network (CSNET). In 1982, the Internet Protocol Suite (TCP/IP) was standardized, which facilitated worldwide proliferation of interconnected networks. TCP/IP network access expanded again in 1986 when the National Science Foundation Network (NSFNet) provided access to supercomputer sites in the United States for researchers, first at speeds of 56 kbit/s and later at 1.5 Mbit/s and 45 Mbit/s. The NSFNet expanded into academic and research organizations in Europe, Australia, New Zealand and Japan in 1988–89. Although other network protocols such as UUCP and PTT public data networks had global reach well before this time, this marked

3737-544: The HyperText Markup Language (HTML), the first Web browser (which was also an HTML editor and could access Usenet newsgroups and FTP files), the first HTTP server software (later known as CERN httpd ), the first web server , and the first Web pages that described the project itself. In 1991 the Commercial Internet eXchange was founded, allowing PSInet to communicate with the other commercial networks CERFnet and Alternet. Stanford Federal Credit Union

3838-495: The International Network Working Group and commercial initiatives led to the development of various protocols and standards by which multiple separate networks could become a single network or "a network of networks". In 1974, Vint Cerf at Stanford University and Bob Kahn at DARPA published a proposal for "A Protocol for Packet Network Intercommunication". They used the term internet as

3939-485: The Merit Network and CYCLADES , were developed in the late 1960s and early 1970s. Early international collaborations for the ARPANET were rare. Connections were made in 1973 to Norway ( NORSAR and NDRE ), and to Peter Kirstein's research group at University College London (UCL), which provided a gateway to British academic networks , forming the first internetwork for resource sharing . ARPA projects,

4040-530: The United States Department of Defense in collaboration with universities and researchers across the United States and in the United Kingdom and France . The ARPANET initially served as a backbone for the interconnection of regional academic and military networks in the United States to enable resource sharing . The funding of the National Science Foundation Network as a new backbone in

4141-438: The high-level programming languages used to create software share a few main characteristics: knowledge of machine code is not necessary to write them, they can be ported to other computer systems, and they are more concise and human-readable than machine code. They must be both human-readable and capable of being translated into unambiguous instructions for computer hardware. The invention of high-level programming languages

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4242-543: The 1980s, as well as private funding for other commercial extensions, encouraged worldwide participation in the development of new networking technologies and the merger of many networks using DARPA's Internet protocol suite . The linking of commercial networks and enterprises by the early 1990s, as well as the advent of the World Wide Web , marked the beginning of the transition to the modern Internet, and generated sustained exponential growth as generations of institutional, personal , and mobile computers were connected to

4343-579: The Internet and the depletion of available IPv4 addresses , a new version of IP IPv6 , was developed in the mid-1990s, which provides vastly larger addressing capabilities and more efficient routing of Internet traffic. IPv6 uses 128 bits for the IP address and was standardized in 1998. IPv6 deployment has been ongoing since the mid-2000s and is currently in growing deployment around the world, since Internet address registries ( RIRs ) began to urge all resource managers to plan rapid adoption and conversion. IPv6

4444-685: The Internet are contained in specially designated RFCs that constitute the Internet Standards . Other less rigorous documents are simply informative, experimental, or historical, or document the best current practices (BCP) when implementing Internet technologies. The Internet carries many applications and services , most prominently the World Wide Web, including social media , electronic mail , mobile applications , multiplayer online games , Internet telephony , file sharing , and streaming media services. Most servers that provide these services are today hosted in data centers , and content

4545-444: The Internet can then be accessed from places such as a park bench. Experiments have also been conducted with proprietary mobile wireless networks like Ricochet , various high-speed data services over cellular networks, and fixed wireless services. Modern smartphones can also access the Internet through the cellular carrier network. For Web browsing, these devices provide applications such as Google Chrome , Safari , and Firefox and

4646-518: The Internet date back to research that enabled the time-sharing of computer resources, the development of packet switching in the 1960s and the design of computer networks for data communication . The set of rules ( communication protocols ) to enable internetworking on the Internet arose from research and development commissioned in the 1970s by the Defense Advanced Research Projects Agency (DARPA) of

4747-618: The Internet for the benefit of all people throughout the world" . Its members include individuals (anyone may join) as well as corporations, organizations , governments, and universities. Among other activities ISOC provides an administrative home for a number of less formally organized groups that are involved in developing and managing the Internet, including: the IETF, Internet Architecture Board (IAB), Internet Engineering Steering Group (IESG), Internet Research Task Force (IRTF), and Internet Research Steering Group (IRSG). On 16 November 2005,

4848-444: The Internet model is the Internet Protocol (IP). IP enables internetworking and, in essence, establishes the Internet itself. Two versions of the Internet Protocol exist, IPv4 and IPv6 . For locating individual computers on the network, the Internet provides IP addresses . IP addresses are used by the Internet infrastructure to direct internet packets to their destinations. They consist of fixed-length numbers, which are found within

4949-514: The Internet via local computer networks. Hotspots providing such access include Wi-Fi cafés, where users need to bring their own wireless devices, such as a laptop or PDA . These services may be free to all, free to customers only, or fee-based. Grassroots efforts have led to wireless community networks . Commercial Wi-Fi services that cover large areas are available in many cities, such as New York , London , Vienna , Toronto , San Francisco , Philadelphia , Chicago and Pittsburgh , where

5050-711: The Internet was included on USA Today ' s list of the New Seven Wonders . The word internetted was used as early as 1849, meaning interconnected or interwoven . The word Internet was used in 1945 by the United States War Department in a radio operator's manual, and in 1974 as the shorthand form of Internetwork. Today, the term Internet most commonly refers to the global system of interconnected computer networks , though it may also refer to any group of smaller networks. When it came into common use, most publications treated

5151-451: The Internet when needed to perform a function or obtain information, represent the bottom of the routing hierarchy. At the top of the routing hierarchy are the tier 1 networks , large telecommunication companies that exchange traffic directly with each other via very high speed fiber-optic cables and governed by peering agreements. Tier 2 and lower-level networks buy Internet transit from other providers to reach at least some parties on

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5252-711: The Internet, the Internet Protocol address (IP address) space and the Domain Name System (DNS), are directed by a maintainer organization, the Internet Corporation for Assigned Names and Numbers (ICANN). The technical underpinning and standardization of the core protocols is an activity of the Internet Engineering Task Force (IETF), a non-profit organization of loosely affiliated international participants that anyone may associate with by contributing technical expertise. In November 2006,

5353-471: The NSFNET and Europe was installed between Cornell University and CERN , allowing much more robust communications than were capable with satellites. Later in 1990, Tim Berners-Lee began writing WorldWideWeb , the first web browser , after two years of lobbying CERN management. By Christmas 1990, Berners-Lee had built all the tools necessary for a working Web: the HyperText Transfer Protocol (HTTP) 0.9,

5454-507: The Pacific and in Africa. The number of unique mobile cellular subscriptions increased from 3.9 billion in 2012 to 4.8 billion in 2016, two-thirds of the world's population, with more than half of subscriptions located in Asia and the Pacific. The number of subscriptions was predicted to rise to 5.7 billion users in 2020. As of 2018 , 80% of the world's population were covered by

5555-861: The UK's national research and education network , JANET . Common methods of Internet access by users include dial-up with a computer modem via telephone circuits, broadband over coaxial cable , fiber optics or copper wires, Wi-Fi , satellite , and cellular telephone technology (e.g. 3G , 4G ). The Internet may often be accessed from computers in libraries and Internet cafés . Internet access points exist in many public places such as airport halls and coffee shops. Various terms are used, such as public Internet kiosk , public access terminal , and Web payphone . Many hotels also have public terminals that are usually fee-based. These terminals are widely accessed for various usages, such as ticket booking, bank deposit, or online payment . Wi-Fi provides wireless access to

5656-826: The United Nations-sponsored World Summit on the Information Society in Tunis established the Internet Governance Forum (IGF) to discuss Internet-related issues. The communications infrastructure of the Internet consists of its hardware components and a system of software layers that control various aspects of the architecture. As with any computer network, the Internet physically consists of routers , media (such as cabling and radio links), repeaters, modems etc. However, as an example of internetworking , many of

5757-672: The United States Department of Defense (DoD). Research into packet switching , one of the fundamental Internet technologies, started in the work of Paul Baran at RAND in the early 1960s and, independently, Donald Davies at the United Kingdom's National Physical Laboratory (NPL) in 1965. After the Symposium on Operating Systems Principles in 1967, packet switching from the proposed NPL network and routing concepts proposed by Baran were incorporated into

5858-461: The United States surpassed those of cable television and nearly exceeded those of broadcast television . Many common online advertising practices are controversial and increasingly subject to regulation. When the Web developed in the 1990s, a typical web page was stored in completed form on a web server, formatted in HTML , ready for transmission to a web browser in response to a request. Over time,

5959-418: The architectural design of the Internet software systems has been assumed by the Internet Engineering Task Force (IETF). The IETF conducts standard-setting work groups, open to any individual, about the various aspects of Internet architecture. The resulting contributions and standards are published as Request for Comments (RFC) documents on the IETF web site. The principal methods of networking that enable

6060-412: The beginning of the Internet as an intercontinental network. Commercial Internet service providers (ISPs) emerged in 1989 in the United States and Australia. The ARPANET was decommissioned in 1990. Steady advances in semiconductor technology and optical networking created new economic opportunities for commercial involvement in the expansion of the network in its core and for delivering services to

6161-399: The bottleneck. The introduction of high-level programming languages in 1958 hid the details of the hardware and expressed the underlying algorithms into the code . Early languages include Fortran , Lisp , and COBOL . There are two main types of software: Software can also be categorized by how it is deployed . Traditional applications are purchased with a perpetual license for

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6262-456: The bottom of the architecture is the link layer , which connects nodes on the same physical link, and contains protocols that do not require routers for traversal to other links. The protocol suite does not explicitly specify hardware methods to transfer bits, or protocols to manage such hardware, but assumes that appropriate technology is available. Examples of that technology include Wi-Fi , Ethernet , and DSL . The most prominent component of

6363-455: The complex array of physical connections that make up its infrastructure, the Internet is facilitated by bi- or multi-lateral commercial contracts, e.g., peering agreements , and by technical specifications or protocols that describe the exchange of data over the network. Indeed, the Internet is defined by its interconnections and routing policies. A subnetwork or subnet is a logical subdivision of an IP network . The practice of dividing

6464-404: The correctness of code, while user acceptance testing helps to ensure that the product meets customer expectations. There are a variety of software development methodologies , which vary from completing all steps in order to concurrent and iterative models. Software development is driven by requirements taken from prospective users, as opposed to maintenance, which is driven by events such as

6565-400: The cost of poor quality software can be as high as 20 to 40 percent of sales. Despite developers' goal of delivering a product that works entirely as intended, virtually all software contains bugs. The rise of the Internet also greatly increased the need for computer security as it enabled malicious actors to conduct cyberattacks remotely. If a bug creates a security risk, it is called

6666-419: The cost of products. Unlike copyrights, patents generally only apply in the jurisdiction where they were issued. Engineer Capers Jones writes that "computers and software are making profound changes to every aspect of human life: education, work, warfare, entertainment, medicine, law, and everything else". It has become ubiquitous in everyday life in developed countries . In many cases, software augments

6767-613: The design of the ARPANET , an experimental resource sharing network proposed by ARPA. ARPANET development began with two network nodes which were interconnected between the University of California, Los Angeles (UCLA) and the Stanford Research Institute (now SRI International) on 29 October 1969. The third site was at the University of California, Santa Barbara , followed by the University of Utah . In

6868-594: The documents and resources that they can provide. HyperText Transfer Protocol (HTTP) is the main access protocol of the World Wide Web. Web services also use HTTP for communication between software systems for information transfer, sharing and exchanging business data and logistics and is one of many languages or protocols that can be used for communication on the Internet. World Wide Web browser software, such as Microsoft 's Internet Explorer / Edge , Mozilla Firefox , Opera , Apple 's Safari , and Google Chrome , enable users to navigate from one web page to another via

6969-485: The first address of a network, followed by a slash character ( / ), and ending with the bit-length of the prefix. For example, 198.51.100.0 / 24 is the prefix of the Internet Protocol version 4 network starting at the given address, having 24 bits allocated for the network prefix, and the remaining 8 bits reserved for host addressing. Addresses in the range 198.51.100.0 to 198.51.100.255 belong to this network. The IPv6 address specification 2001:db8:: / 32

7070-438: The form of commercial off-the-shelf (COTS) or open-source software . Software quality assurance is typically a combination of manual code review by other engineers and automated software testing . Due to time constraints, testing cannot cover all aspects of the software's intended functionality, so developers often focus on the most critical functionality. Formal methods are used in some safety-critical systems to prove

7171-429: The forwarding host (router) to other networks when no other route specification matches the destination IP address of a packet. While the hardware components in the Internet infrastructure can often be used to support other software systems, it is the design and the standardization process of the software that characterizes the Internet and provides the foundation for its scalability and success. The responsibility for

7272-439: The functionality of existing technologies such as household appliances and elevators . Software also spawned entirely new technologies such as the Internet , video games , mobile phones , and GPS . New methods of communication, including email , forums , blogs , microblogging , wikis , and social media , were enabled by the Internet. Massive amounts of knowledge exceeding any paper-based library are now available with

7373-603: The global Internet, though they may also engage in peering. An ISP may use a single upstream provider for connectivity, or implement multihoming to achieve redundancy and load balancing. Internet exchange points are major traffic exchanges with physical connections to multiple ISPs. Large organizations, such as academic institutions, large enterprises, and governments, may perform the same function as ISPs, engaging in peering and purchasing transit on behalf of their internal networks. Research networks tend to interconnect with large subnetworks such as GEANT , GLORIAD , Internet2 , and

7474-570: The hardware. The introduction of high-level programming languages in 1958 allowed for more human-readable instructions, making software development easier and more portable across different computer architectures . Software in a programming language is run through a compiler or interpreter to execute on the architecture's hardware. Over time, software has become complex, owing to developments in networking , operating systems , and databases . Software can generally be categorized into two main types: The rise of cloud computing has introduced

7575-661: The hope that visitors will be impressed by the expert knowledge and free information and be attracted to the corporation as a result. Advertising on popular web pages can be lucrative, and e-commerce , which is the sale of products and services directly via the Web, continues to grow. Online advertising is a form of marketing and advertising which uses the Internet to deliver promotional marketing messages to consumers. It includes email marketing, search engine marketing (SEM), social media marketing, many types of display advertising (including web banner advertising), and mobile advertising . In 2011, Internet advertising revenues in

7676-505: The hyperlinks embedded in the documents. These documents may also contain any combination of computer data , including graphics, sounds, text , video , multimedia and interactive content that runs while the user is interacting with the page. Client-side software can include animations, games , office applications and scientific demonstrations. Through keyword -driven Internet research using search engines like Yahoo! , Bing and Google , users worldwide have easy, instant access to

7777-485: The late 1990s, it was estimated that traffic on the public Internet grew by 100 percent per year, while the mean annual growth in the number of Internet users was thought to be between 20% and 50%. This growth is often attributed to the lack of central administration, which allows organic growth of the network, as well as the non-proprietary nature of the Internet protocols, which encourages vendor interoperability and prevents any one company from exerting too much control over

7878-597: The mid-1970s and is vested in the company that makes the software, not the employees or contractors who wrote it. The use of most software is governed by an agreement ( software license ) between the copyright holder and the user. Proprietary software is usually sold under a restrictive license that limits copying and reuse (often enforced with tools such as digital rights management (DRM)). Open-source licenses , in contrast, allow free use and redistribution of software with few conditions. Most open-source licenses used for software require that modifications be released under

7979-462: The network nodes are not necessarily Internet equipment per se. The internet packets are carried by other full-fledged networking protocols with the Internet acting as a homogeneous networking standard, running across heterogeneous hardware, with the packets guided to their destinations by IP routers. Internet service providers (ISPs) establish the worldwide connectivity between individual networks at various levels of scope. End-users who only access

8080-412: The network. As of 31 March 2011 , the estimated total number of Internet users was 2.095 billion (30% of world population ). It is estimated that in 1993 the Internet carried only 1% of the information flowing through two-way telecommunication . By 2000 this figure had grown to 51%, and by 2007 more than 97% of all telecommunicated information was carried over the Internet. The Internet

8181-1058: The network. Although the Internet was widely used by academia in the 1980s, the subsequent commercialization in the 1990s and beyond incorporated its services and technologies into virtually every aspect of modern life. Most traditional communication media, including telephone , radio , television , paper mail, and newspapers, are reshaped, redefined, or even bypassed by the Internet, giving birth to new services such as email , Internet telephone , Internet television , online music , digital newspapers, and video streaming websites. Newspapers, books, and other print publishing have adapted to website technology or have been reshaped into blogging , web feeds , and online news aggregators . The Internet has enabled and accelerated new forms of personal interaction through instant messaging , Internet forums , and social networking services . Online shopping has grown exponentially for major retailers, small businesses , and entrepreneurs , as it enables firms to extend their " brick and mortar " presence to serve

8282-414: The networking technologies that interconnect networks at their borders and exchange traffic across them. The Internet layer implements the Internet Protocol (IP) which enables computers to identify and locate each other by IP address and route their traffic via intermediate (transit) networks. The Internet Protocol layer code is independent of the type of network that it is physically running over. At

8383-577: The new software delivery model Software as a Service (SaaS). In SaaS, applications are hosted by a provider and accessed over the Internet . The process of developing software involves several stages. The stages include software design , programming , testing , release , and maintenance . Software quality assurance and security are critical aspects of software development, as bugs and security vulnerabilities can lead to system failures and security breaches. Additionally, legal issues such as software licenses and intellectual property rights play

8484-472: The operating system) can take this saved file and execute it as a process on the computer hardware. Some programming languages use an interpreter instead of a compiler. An interpreter converts the program into machine code at run time , which makes them 10 to 100 times slower than compiled programming languages. Software is often released with the knowledge that it is incomplete or contains bugs. Purchasers knowingly buy it in this state, which has led to

8585-481: The packet. IP addresses are generally assigned to equipment either automatically via DHCP , or are configured. However, the network also supports other addressing systems. Users generally enter domain names (e.g. "en.wikipedia.org") instead of IP addresses because they are easier to remember; they are converted by the Domain Name System (DNS) into IP addresses which are more efficient for routing purposes. Internet Protocol version 4 (IPv4) defines an IP address as

8686-555: The physical world may also be part of the requirements for a software patent to be held valid. Software patents have been historically controversial . Before the 1998 case State Street Bank & Trust Co. v. Signature Financial Group, Inc. , software patents were generally not recognized in the United States. In that case, the Supreme Court decided that business processes could be patented. Patent applications are complex and costly, and lawsuits involving patents can drive up

8787-435: The principal name spaces of the Internet are administered by the Internet Corporation for Assigned Names and Numbers (ICANN). ICANN is governed by an international board of directors drawn from across the Internet technical, business, academic, and other non-commercial communities. ICANN coordinates the assignment of unique identifiers for use on the Internet, including domain names , IP addresses, application port numbers in

8888-586: The process of creating and serving web pages has become dynamic, creating a flexible design, layout, and content. Websites are often created using content management software with, initially, very little content. Contributors to these systems, who may be paid staff, members of an organization or the public, fill underlying databases with content using editing pages designed for that purpose while casual visitors view and read this content in HTML form. There may or may not be editorial, approval and security systems built into

8989-442: The public. In mid-1989, MCI Mail and Compuserve established connections to the Internet, delivering email and public access products to the half million users of the Internet. Just months later, on 1 January 1990, PSInet launched an alternate Internet backbone for commercial use; one of the networks that added to the core of the commercial Internet of later years. In March 1990, the first high-speed T1 (1.5 Mbit/s) link between

9090-469: The region had a handful of plans to choose from (across all mobile network operators) while others, such as Colombia , offered as many as 30 pre-paid and 34 post-paid plans. A study of eight countries in the Global South found that zero-rated data plans exist in every country, although there is a great range in the frequency with which they are offered and actually used in each. The study looked at

9191-408: The release. Over time, the level of maintenance becomes increasingly restricted before being cut off entirely when the product is withdrawn from the market. As software ages , it becomes known as legacy software and can remain in use for decades, even if there is no one left who knows how to fix it. Over the lifetime of the product, software maintenance is estimated to comprise 75 percent or more of

9292-590: The rise of near-instant communication by email, instant messaging , telephony ( Voice over Internet Protocol or VoIP), two-way interactive video calls , and the World Wide Web with its discussion forums , blogs, social networking services , and online shopping sites. Increasing amounts of data are transmitted at higher and higher speeds over fiber optic networks operating at 1 Gbit/s, 10 Gbit/s, or more. The Internet continues to grow, driven by ever-greater amounts of online information and knowledge, commerce, entertainment and social networking services. During

9393-424: The same license, which can create complications when open-source software is reused in proprietary projects. Patents give an inventor an exclusive, time-limited license for a novel product or process. Ideas about what software could accomplish are not protected by law and concrete implementations are instead covered by copyright law . In some countries, a requirement for the claimed invention to have an effect on

9494-452: The subnet mask for the prefix 198.51.100.0 / 24 . Traffic is exchanged between subnetworks through routers when the routing prefixes of the source address and the destination address differ. A router serves as a logical or physical boundary between the subnets. The benefits of subnetting an existing network vary with each deployment scenario. In the address allocation architecture of the Internet using CIDR and in large organizations, it

9595-462: The top three to five carriers by market share in Bangladesh, Colombia, Ghana, India, Kenya, Nigeria, Peru and Philippines. Across the 181 plans examined, 13 percent were offering zero-rated services. Another study, covering Ghana , Kenya , Nigeria and South Africa , found Facebook 's Free Basics and Misplaced Pages Zero to be the most commonly zero-rated content. The Internet standards describe

9696-431: The total development cost. Completing a software project involves various forms of expertise, not just in software programmers but also testing, documentation writing, project management , graphic design , user experience , user support, marketing , and fundraising. Software quality is defined as meeting the stated requirements as well as customer expectations. Quality is an overarching term that can refer to

9797-405: The transport protocols, and many other parameters. Globally unified name spaces are essential for maintaining the global reach of the Internet. This role of ICANN distinguishes it as perhaps the only central coordinating body for the global Internet. Regional Internet registries (RIRs) were established for five regions of the world. The African Network Information Center (AfriNIC) for Africa ,

9898-455: The volume of Internet traffic started experiencing similar characteristics as that of the scaling of MOS transistors , exemplified by Moore's law , doubling every 18 months. This growth, formalized as Edholm's law , was catalyzed by advances in MOS technology , laser light wave systems, and noise performance. Since 1995, the Internet has tremendously impacted culture and commerce, including

9999-533: The word Internet as a capitalized proper noun ; this has become less common. This reflects the tendency in English to capitalize new terms and move them to lowercase as they become familiar. The word is sometimes still capitalized to distinguish the global internet from smaller networks, though many publications, including the AP Stylebook since 2016, recommend the lowercase form in every case. In 2016,

10100-401: Was simultaneous with the compilers needed to translate them automatically into machine code. Most programs do not contain all the resources needed to run them and rely on external libraries . Part of the compiler's function is to link these files in such a way that the program can be executed by the hardware. Once compiled, the program can be saved as an object file and the loader (part of

10201-558: Was the first financial institution to offer online Internet banking services to all of its members in October 1994. In 1996, OP Financial Group , also a cooperative bank , became the second online bank in the world and the first in Europe. By 1995, the Internet was fully commercialized in the U.S. when the NSFNet was decommissioned, removing the last restrictions on use of the Internet to carry commercial traffic. As technology advanced and commercial opportunities fueled reciprocal growth,

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