81-466: In information technology , a backup , or data backup is a copy of computer data taken and stored elsewhere so that it may be used to restore the original after a data loss event. The verb form, referring to the process of doing so, is " back up ", whereas the noun and adjective form is " backup ". Backups can be used to recover data after its loss from data deletion or corruption , or to recover data from an earlier time. Backups provide
162-438: A backup rotation scheme , which is a system of backing up data to computer media that limits the number of backups of different dates retained separately, by appropriate re-use of the data storage media by overwriting of backups no longer needed. The scheme determines how and when each piece of removable storage is used for a backup operation and how long it is retained once it has backup data stored on it. The 3-2-1 rule can aid in
243-419: A disk array (maybe connected to SAN ) is an example of an online backup. This type of storage is convenient and speedy, but is vulnerable to being deleted or overwritten, either by accident, by malevolent action, or in the wake of a data-deleting virus payload. Nearline storage is typically less accessible and less expensive than online storage, but still useful for backup data storage. A mechanical device
324-416: A balance between accessibility, security and cost. These media management methods are not mutually exclusive and are frequently combined to meet the user's needs. Using on-line disks for staging data before it is sent to a near-line tape library is a common example. Online backup storage is typically the most accessible type of data storage, and can begin a restore in milliseconds. An internal hard disk or
405-618: A business context, the Information Technology Association of America has defined information technology as "the study, design, development, application, implementation, support, or management of computer-based information systems". The responsibilities of those working in the field include network administration, software development and installation, and the planning and management of an organization's technology life cycle, by which hardware and software are maintained, upgraded, and replaced. Information services
486-404: A cable. Because the data is not accessible via any computer except during limited periods in which they are written or read back, they are largely immune to on-line backup failure modes. Access time varies depending on whether the media are on-site or off-site. Backup media may be sent to an off-site vault to protect against a disaster or other site-specific problem. The vault can be as simple as
567-542: A complete computing machine. During the Second World War , Colossus developed the first electronic digital computer to decrypt German messages. Although it was programmable , it was not general-purpose, being designed to perform only a single task. It also lacked the ability to store its program in memory; programming was carried out using plugs and switches to alter the internal wiring. The first recognizably modern electronic digital stored-program computer
648-475: A component of their 305 RAMAC computer system. Most digital data today is still stored magnetically on hard disks, or optically on media such as CD-ROMs . Until 2002 most information was stored on analog devices , but that year digital storage capacity exceeded analog for the first time. As of 2007 , almost 94% of the data stored worldwide was held digitally: 52% on hard disks, 28% on optical devices, and 11% on digital magnetic tape. It has been estimated that
729-466: A corrupted file that is unusable. This is also the case across interrelated files, as may be found in a conventional database or in applications such as Microsoft Exchange Server . The term fuzzy backup can be used to describe a backup of live data that looks like it ran correctly, but does not represent the state of the data at a single point in time. Backup options for data files that cannot be or are not quiesced include: Not all information stored on
810-417: A data security risk if they are lost or stolen. Encrypting the data on these media can mitigate this problem, however encryption is a CPU intensive process that can slow down backup speeds, and the security of the encrypted backups is only as effective as the security of the key management policy. When there are many more computers to be backed up than there are destination storage devices, the ability to use
891-443: A fault of the drive typically just halts the spinning. Optical media is modular ; the storage controller is not tied to media itself like with hard drives or flash storage (→ flash memory controller ), allowing it to be removed and accessed through a different drive. However, recordable media may degrade earlier under long-term exposure to light. Some optical storage systems allow for cataloged data backups without human contact with
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#1732790393333972-407: A layer of data protection. However, the users must trust the provider to maintain the privacy and integrity of their data, with confidentiality enhanced by the use of encryption . Because speed and availability are limited by a user's online connection, users with large amounts of data may need to use cloud seeding and large-scale recovery. Various methods can be used to manage backup media, striking
1053-403: A limited period of time, so an offsite copy still remains as the ideal choice. Because there is no perfect storage, many backup experts recommend maintaining a second copy on a local physical device, even if the data is also backed up offsite. An unstructured repository may simply be a stack of tapes, DVD-Rs or external HDDs with minimal information about what was backed up and when. This method
1134-450: A more efficient manner are usually seen as "just the cost of doing business." IT departments are allocated funds by senior leadership and must attempt to achieve the desired deliverables while staying within that budget. Government and the private sector might have different funding mechanisms, but the principles are more-or-less the same. This is an often overlooked reason for the rapid interest in automation and Artificial Intelligence , but
1215-473: A particular letter; possible delays in message delivery (up to several days); limits on the size of one message and on the total size of messages in the mailbox (personal for users). A software and hardware complex with a web interface that provides the ability to search for information on the Internet. A search engine usually means a site that hosts the interface (front-end) of the system. The software part of
1296-405: A search engine is a search engine (search engine) — a set of programs that provides the functionality of a search engine and is usually a trade secret of the search engine developer company. Most search engines look for information on World Wide Web sites, but there are also systems that can look for files on FTP servers, items in online stores, and information on Usenet newsgroups. Improving search
1377-497: A shock-absorbing case around the hard disk, and claim a range of higher drop specifications. Over a period of years the stability of hard disk backups is shorter than that of tape backups. External hard disks can be connected via local interfaces like SCSI , USB , FireWire , or eSATA , or via longer-distance technologies like Ethernet , iSCSI , or Fibre Channel . Some disk-based backup systems, via Virtual Tape Libraries or otherwise, support data deduplication, which can reduce
1458-526: A simple form of IT disaster recovery ; however not all backup systems are able to reconstitute a computer system or other complex configuration such as a computer cluster , active directory server, or database server . A backup system contains at least one copy of all data considered worth saving. The data storage requirements can be large. An information repository model may be used to provide structure to this storage. There are different types of data storage devices used for copying backups of data that
1539-416: A single storage device with several simultaneous backups can be useful. However cramming the scheduled backup window via "multiplexed backup" is only used for tape destinations. The process of rearranging the sets of backups in an archive file is known as refactoring. For example, if a backup system uses a single tape each day to store the incremental backups for all the protected computers, restoring one of
1620-485: A standard configuration to many systems rather than as a tool for making ongoing backups of diverse systems. An incremental backup stores data changed since a reference point in time. Duplicate copies of unchanged data are not copied. Typically a full backup of all files is made once or at infrequent intervals, serving as the reference point for an incremental repository. Subsequently, a number of incremental backups are made after successive time periods. Restores begin with
1701-406: A system administrator's home office or as sophisticated as a disaster-hardened, temperature-controlled, high-security bunker with facilities for backup media storage. A data replica can be off-site but also on-line (e.g., an off-site RAID mirror). A backup site or disaster recovery center is used to store data that can enable computer systems and networks to be restored and properly configured in
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#17327903933331782-464: A technology now obsolete. Electronic data storage, which is used in modern computers, dates from World War II, when a form of delay-line memory was developed to remove the clutter from radar signals, the first practical application of which was the mercury delay line. The first random-access digital storage device was the Williams tube , which was based on a standard cathode ray tube . However,
1863-607: Is a problem matching the speed of the final destination device with the source device, as is frequently faced in network-based backup systems. It can also serve as a centralized location for applying other data manipulation techniques. About backup Related topics Information technology Information technology ( IT ) is a set of related fields that encompass computer systems, software , programming languages , and data and information processing, and storage. IT forms part of information and communications technology (ICT). An information technology system ( IT system )
1944-487: Is a term somewhat loosely applied to a variety of IT-related services offered by commercial companies, as well as data brokers . The field of information ethics was established by mathematician Norbert Wiener in the 1940s. Some of the ethical issues associated with the use of information technology include: Research suggests that IT projects in business and public administration can easily become significant in scale. Work conducted by McKinsey in collaboration with
2025-503: Is already in secondary storage onto archive files . There are also different ways these devices can be arranged to provide geographic dispersion, data security , and portability . Data is selected, extracted, and manipulated for storage. The process can include methods for dealing with live data , including open files, as well as compression, encryption, and de-duplication . Additional techniques apply to enterprise client-server backup . Backup schemes may include dry runs that validate
2106-433: Is also worth noting that from a business perspective, Information technology departments are a " cost center " the majority of the time. A cost center is a department or staff which incurs expenses, or "costs", within a company rather than generating profits or revenue streams. Modern businesses rely heavily on technology for their day-to-day operations, so the expenses delegated to cover technology that facilitates business in
2187-412: Is an appended ".bak" extension to the file name . A Reverse incremental backup method stores a recent archive file "mirror" of the source data and a series of differences between the "mirror" in its current state and its previous states. A reverse incremental backup method starts with a non-image full backup. After the full backup is performed, the system periodically synchronizes the full backup with
2268-566: Is commonly held in relational databases to take advantage of their "robust implementation verified by years of both theoretical and practical effort." As an evolution of the Standard Generalized Markup Language (SGML), XML's text-based structure offers the advantage of being both machine- and human-readable . Data transmission has three aspects: transmission, propagation, and reception. It can be broadly categorized as broadcasting , in which information
2349-768: Is generally an information system , a communications system , or, more specifically speaking, a computer system — including all hardware , software , and peripheral equipment — operated by a limited group of IT users, and an IT project usually refers to the commissioning and implementation of an IT system. IT systems play a vital role in facilitating efficient data management, enhancing communication networks, and supporting organizational processes across various industries. Successful IT projects require meticulous planning, seamless integration, and ongoing maintenance to ensure optimal functionality and alignment with organizational objectives. Although humans have been storing, retrieving, manipulating, and communicating information since
2430-507: Is one of the priorities of the modern Internet (see the Deep Web article about the main problems in the work of search engines). Companies in the information technology field are often discussed as a group as the "tech sector" or the "tech industry." These titles can be misleading at times and should not be mistaken for "tech companies;" which are generally large scale, for-profit corporations that sell consumer technology and software. It
2511-424: Is still widely deployed more than 50 years later. IMS stores data hierarchically , but in the 1970s Ted Codd proposed an alternative relational storage model based on set theory and predicate logic and the familiar concepts of tables, rows, and columns. In 1981, the first commercially available relational database management system (RDBMS) was released by Oracle . All DMS consist of components, they allow
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2592-447: Is stored in discrete units, known as files . These files are organized into filesystems . Deciding what to back up at any given time involves tradeoffs. By backing up too much redundant data, the information repository will fill up too quickly. Backing up an insufficient amount of data can eventually lead to the loss of critical information. Files that are actively being updated present a challenge to back up. One way to back up live data
2673-546: Is the IBM 3592 (also referred to as the TS11xx series). The Oracle StorageTek T10000 was discontinued in 2016. The use of hard disk storage has increased over time as it has become progressively cheaper. Hard disks are usually easy to use, widely available, and can be accessed quickly. However, hard disk backups are close-tolerance mechanical devices and may be more easily damaged than tapes, especially while being transported. In
2754-411: Is the easiest to implement, but unlikely to achieve a high level of recoverability as it lacks automation. A repository using this backup method contains complete source data copies taken at one or more specific points in time. Copying system images , this method is frequently used by computer technicians to record known good configurations. However, imaging is generally more useful as a way of deploying
2835-425: Is to temporarily quiesce them (e.g., close all files), take a "snapshot", and then resume live operations. At this point the snapshot can be backed up through normal methods. A snapshot is an instantaneous function of some filesystems that presents a copy of the filesystem as if it were frozen at a specific point in time, often by a copy-on-write mechanism. Snapshotting a file while it is being changed results in
2916-417: Is transmitted unidirectionally downstream, or telecommunications , with bidirectional upstream and downstream channels. XML has been increasingly employed as a means of data interchange since the early 2000s, particularly for machine-oriented interactions such as those involved in web-oriented protocols such as SOAP , describing "data-in-transit rather than... data-at-rest". Hilbert and Lopez identify
2997-404: Is usually used to move media units from storage into a drive where the data can be read or written. Generally it has safety properties similar to on-line storage. An example is a tape library with restore times ranging from seconds to a few minutes. Off-line storage requires some direct action to provide access to the storage media: for example, inserting a tape into a tape drive or plugging in
3078-454: The Internet , which was equivalent to 51 million households. Along with the Internet, new types of technology were also being introduced across the globe, which has improved efficiency and made things easier across the globe. Along with technology revolutionizing society, millions of processes could be done in seconds. Innovations in communication were also crucial as people began to rely on
3159-432: The 16th century, and it was not until 1645 that the first mechanical calculator capable of performing the four basic arithmetical operations was developed. Electronic computers , using either relays or valves , began to appear in the early 1940s. The electromechanical Zuse Z3 , completed in 1941, was the world's first programmable computer, and by modern standards one of the first machines that could be considered
3240-410: The Internet alone while e-commerce a decade later resulted in $ 289 billion in sales. And as computers are rapidly becoming more sophisticated by the day, they are becoming more used as people are becoming more reliant on them during the twenty-first century. Early electronic computers such as Colossus made use of punched tape , a long strip of paper on which data was represented by a series of holes,
3321-417: The ability to transfer both plain text and formatted, as well as arbitrary files; independence of servers (in the general case, they address each other directly); sufficiently high reliability of message delivery; ease of use by humans and programs. Disadvantages of e-mail: the presence of such a phenomenon as spam (massive advertising and viral mailings); the theoretical impossibility of guaranteed delivery of
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3402-484: The accumulated changes in data) increases, so does the time to perform the differential backup. Restoring an entire system requires starting from the most recent full backup and then applying just the last differential backup. A differential backup copies files that have been created or changed since the last full backup, regardless of whether any other differential backups have been made since, whereas an incremental backup copies files that have been created or changed since
3483-505: The amount of disk storage capacity consumed by daily and weekly backup data. Optical storage uses lasers to store and retrieve data. Recordable CDs , DVDs, and Blu-ray Discs are commonly used with personal computers and are generally cheap. The capacities and speeds of these discs have typically been lower than hard disks or tapes. Advances in optical media may shrink that gap in the future. Potential future data losses caused by gradual media degradation can be predicted by measuring
3564-527: The appearance of the term in 1990 contained within documents for the International Organization for Standardization (ISO). Innovations in technology have already revolutionized the world by the twenty-first century as people were able to access different online services. This has changed the workforce drastically as thirty percent of U.S. workers were already in careers in this profession. 136.9 million people were personally connected to
3645-567: The application of statistical and mathematical methods to decision-making , and the simulation of higher-order thinking through computer programs. The term is commonly used as a synonym for computers and computer networks , but it also encompasses other information distribution technologies such as television and telephones . Several products or services within an economy are associated with information technology, including computer hardware , software , electronics, semiconductors, internet , telecom equipment , and e-commerce . Based on
3726-799: The backup process. It states that there should be at least 3 copies of the data, stored on 2 different types of storage media, and one copy should be kept offsite, in a remote location (this can include cloud storage ). 2 or more different media should be used to eliminate data loss due to similar reasons (for example, optical discs may tolerate being underwater while LTO tapes may not, and SSDs cannot fail due to head crashes or damaged spindle motors since they do not have any moving parts, unlike hard drives). An offsite copy protects against fire, theft of physical media (such as tapes or discs) and natural disasters like floods and earthquakes. Physically protected hard drives are an alternative to an offsite copy, but they have limitations like only being able to resist fire for
3807-674: The computer is stored in files. Accurately recovering a complete system from scratch requires keeping track of this non-file data too. It is frequently useful or required to manipulate the data being backed up to optimize the backup process. These manipulations can improve backup speed, restore speed, data security, media usage and/or reduced bandwidth requirements. Out-of-date data can be automatically deleted, but for personal backup applications—as opposed to enterprise client-server backup applications where automated data "grooming" can be customized—the deletion can at most be globally delayed or be disabled. Various schemes can be employed to shrink
3888-464: The computer to communicate through telephone lines and cable. The introduction of the email was considered revolutionary as "companies in one part of the world could communicate by e-mail with suppliers and buyers in another part of the world..." Not only personally, computers and technology have also revolutionized the marketing industry, resulting in more buyers of their products. During the year of 2002, Americans exceeded $ 28 billion in goods just over
3969-456: The computers could require many tapes. Refactoring could be used to consolidate all the backups for a single computer onto a single tape, creating a "synthetic full backup". This is especially useful for backup systems that do incrementals forever style backups. Sometimes backups are copied to a staging disk before being copied to tape. This process is sometimes referred to as D2D2T, an acronym for Disk-to-disk-to-tape . It can be useful if there
4050-646: The consistency of live data, protecting self-consistent files but requiring applications "be quiesced and made ready for backup." Near-CDP is more practicable for ordinary personal backup applications, as opposed to true CDP, which must be run in conjunction with a virtual machine or equivalent and is therefore generally used in enterprise client-server backups. Software may create copies of individual files such as written documents, multimedia projects, or user preferences, to prevent failed write events caused by power outages, operating system crashes, or exhausted disk space, from causing data loss. A common implementation
4131-419: The constant pressure to do more with less is opening the door for automation to take control of at least some minor operations in large companies. Many companies now have IT departments for managing the computers , networks, and other technical areas of their businesses. Companies have also sought to integrate IT with business outcomes and decision-making through a BizOps or business operations department. In
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#17327903933334212-406: The data frozen at a particular point in time . Near-CDP (except for Apple Time Machine ) intent-logs every change on the host system, often by saving byte or block-level differences rather than file-level differences. This backup method differs from simple disk mirroring in that it enables a roll-back of the log and thus a restoration of old images of data. Intent-logging allows precautions for
4293-409: The data has to be copied onto an archive file data storage medium. The medium used is also referred to as the type of backup destination. Magnetic tape was for a long time the most commonly used medium for bulk data storage, backup, archiving, and interchange. It was previously a less expensive option, but this is no longer the case for smaller amounts of data. Tape is a sequential access medium, so
4374-431: The data they store to be accessed simultaneously by many users while maintaining its integrity. All databases are common in one point that the structure of the data they contain is defined and stored separately from the data itself, in a database schema . In recent years, the extensible markup language (XML) has become a popular format for data representation. Although XML data can be stored in normal file systems , it
4455-474: The data. This allows restoration of data to any point in time and is the most comprehensive and advanced data protection. Near-CDP backup applications—often marketed as "CDP"—automatically take incremental backups at a specific interval, for example every 15 minutes, one hour, or 24 hours. They can therefore only allow restores to an interval boundary. Near-CDP backup applications use journaling and are typically based on periodic "snapshots", read-only copies of
4536-1305: The discs, allowing for longer data integrity. A French study in 2008 indicated that the lifespan of typically-sold CD-Rs was 2–10 years, but one manufacturer later estimated the longevity of its CD-Rs with a gold-sputtered layer to be as high as 100 years. Sony's proprietary Optical Disc Archive can in 2016 reach a read rate of 250 MB/s. Solid-state drives (SSDs) use integrated circuit assemblies to store data. Flash memory , thumb drives , USB flash drives , CompactFlash , SmartMedia , Memory Sticks , and Secure Digital card devices are relatively expensive for their low capacity, but convenient for backing up relatively low data volumes. A solid-state drive does not contain any movable parts, making it less susceptible to physical damage, and can have huge throughput of around 500 Mbit/s up to 6 Gbit/s. Available SSDs have become more capacious and cheaper. Flash memory backups are stable for fewer years than hard disk backups. Remote backup services or cloud backups involve service providers storing data offsite. This has been used to protect against events such as fires, floods, or earthquakes which could destroy locally stored backups. Cloud-based backup (through services like or similar to Google Drive , and Microsoft OneDrive ) provides
4617-504: The earliest writing systems were developed, the term information technology in its modern sense first appeared in a 1958 article published in the Harvard Business Review ; authors Harold J. Leavitt and Thomas L. Whisler commented that "the new technology does not yet have a single established name. We shall call it information technology (IT)." Their definition consists of three categories: techniques for processing,
4698-566: The emergence of information and communications technology (ICT). By the year of 1984, according to the National Westminster Bank Quarterly Review , the term information technology had been redefined as "The development of cable television was made possible by the convergence of telecommunications and computing technology (…generally known in Britain as information technology)." We then begin to see
4779-502: The event of a disaster. Some organisations have their own data recovery centres, while others contract this out to a third-party. Due to high costs, backing up is rarely considered the preferred method of moving data to a DR site. A more typical way would be remote disk mirroring , which keeps the DR data as up to date as possible. A backup operation starts with selecting and extracting coherent units of data. Most data on modern computer systems
4860-404: The exponential pace of technological change (a kind of Moore's law ): machines' application-specific capacity to compute information per capita roughly doubled every 14 months between 1986 and 2007; the per capita capacity of the world's general-purpose computers doubled every 18 months during the same two decades; the global telecommunication capacity per capita doubled every 34 months;
4941-455: The field of data mining — "the process of discovering interesting patterns and knowledge from large amounts of data" — emerged in the late 1980s. The technology and services it provides for sending and receiving electronic messages (called "letters" or "electronic letters") over a distributed (including global) computer network. In terms of the composition of elements and the principle of operation, electronic mail practically repeats
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#17327903933335022-455: The first planar silicon dioxide transistors by Frosch and Derick in 1957, the MOSFET demonstration by a Bell Labs team. the planar process by Jean Hoerni in 1959, and the microprocessor invented by Ted Hoff , Federico Faggin , Masatoshi Shima , and Stanley Mazor at Intel in 1971. These important inventions led to the development of the personal computer (PC) in the 1970s, and
5103-501: The first transistorized computer developed at the University of Manchester and operational by November 1953, consumed only 150 watts in its final version. Several other breakthroughs in semiconductor technology include the integrated circuit (IC) invented by Jack Kilby at Texas Instruments and Robert Noyce at Fairchild Semiconductor in 1959, silicon dioxide surface passivation by Carl Frosch and Lincoln Derick in 1955,
5184-488: The information stored in it and delay-line memory was volatile in the fact that it had to be continuously refreshed, and thus was lost once power was removed. The earliest form of non-volatile computer storage was the magnetic drum , invented in 1932 and used in the Ferranti Mark 1 , the world's first commercially available general-purpose electronic computer. IBM introduced the first hard disk drive in 1956, as
5265-538: The introduction of computer science-related courses in K-12 education . Ideas of computer science were first mentioned before the 1950s under the Massachusetts Institute of Technology (MIT) and Harvard University , where they had discussed and began thinking of computer circuits and numerical calculations. As time went on, the field of information technology and computer science became more complex and
5346-409: The last full backup and then apply the incrementals. Some backup systems can create a synthetic full backup from a series of incrementals, thus providing the equivalent of frequently doing a full backup. When done to modify a single archive file, this speeds restores of recent versions of files. Continuous Data Protection (CDP) refers to a backup that instantly saves a copy of every change made to
5427-404: The live copy, while storing the data necessary to reconstruct older versions. This can either be done using hard links —as Apple Time Machine does, or using binary diffs . A differential backup saves only the data that has changed since the last full backup. This means a maximum of two backups from the repository are used to restore the data. However, as time from the last full backup (and thus
5508-429: The mid-2000s, several drive manufacturers began to produce portable drives employing ramp loading and accelerometer technology (sometimes termed a "shock sensor"), and by 2010 the industry average in drop tests for drives with that technology showed drives remaining intact and working after a 36-inch non-operating drop onto industrial carpeting. Some manufacturers also offer 'ruggedized' portable hard drives, which include
5589-400: The most recent backup of any type (full or incremental). Changes in files may be detected through a more recent date/time of last modification file attribute , and/or changes in file size. Other variations of incremental backup include multi-level incrementals and block-level incrementals that compare parts of files instead of just entire files. Regardless of the repository model that is used,
5670-446: The rate of continuously writing or reading data can be very fast. While tape media itself has a low cost per space, tape drives are typically dozens of times as expensive as hard disk drives and optical drives . Many tape formats have been proprietary or specific to certain markets like mainframes or a particular brand of personal computer. By 2014 LTO had become the primary tape technology. The other remaining viable "super" format
5751-431: The rate of correctable minor data errors , of which consecutively too many increase the risk of uncorrectable sectors. Support for error scanning varies among optical drive vendors. Many optical disc formats are WORM type, which makes them useful for archival purposes since the data cannot be changed. Moreover, optical discs are not vulnerable to head crashes , magnetism, imminent water ingress or power surges ; and,
5832-474: The reliability of the data being backed up. There are limitations and human factors involved in any backup scheme. A backup strategy requires an information repository, "a secondary storage space for data" that aggregates backups of data "sources". The repository could be as simple as a list of all backup media (DVDs, etc.) and the dates produced, or could include a computerized index, catalog, or relational database . The backup data needs to be stored, requiring
5913-616: The size of the source data to be stored so that it uses less storage space. Compression is frequently a built-in feature of tape drive hardware. Redundancy due to backing up similarly configured workstations can be reduced, thus storing just one copy. This technique can be applied at the file or raw block level. This potentially large reduction is called deduplication . It can occur on a server before any data moves to backup media, sometimes referred to as source/client side deduplication. This approach also reduces bandwidth required to send backup data to its target media. The process can also occur at
5994-503: The storage and processing technologies employed, it is possible to distinguish four distinct phases of IT development: pre-mechanical (3000 BC — 1450 AD), mechanical (1450 — 1840), electromechanical (1840 — 1940), and electronic (1940 to present). Information technology is a branch of computer science , defined as the study of procedures, structures, and the processing of various types of data. As this field continues to evolve globally, its priority and importance have grown, leading to
6075-417: The system of regular (paper) mail, borrowing both terms (mail, letter, envelope, attachment, box, delivery, and others) and characteristic features — ease of use, message transmission delays, sufficient reliability and at the same time no guarantee of delivery. The advantages of e-mail are: easily perceived and remembered by a person addresses of the form user_name@domain_name (for example, somebody@example.com);
6156-460: The target storage device, sometimes referred to as inline or back-end deduplication. Sometimes backups are duplicated to a second set of storage media. This can be done to rearrange the archive files to optimize restore speed, or to have a second copy at a different location or on a different storage medium—as in the disk-to-disk-to-tape capability of Enterprise client-server backup. High-capacity removable storage media such as backup tapes present
6237-405: The world's storage capacity per capita required roughly 40 months to double (every 3 years); and per capita broadcast information has doubled every 12.3 years. Massive amounts of data are stored worldwide every day, but unless it can be analyzed and presented effectively it essentially resides in what have been called data tombs: "data archives that are seldom visited". To address that issue,
6318-403: The worldwide capacity to store information on electronic devices grew from less than 3 exabytes in 1986 to 295 exabytes in 2007, doubling roughly every 3 years. Database Management Systems (DMS) emerged in the 1960s to address the problem of storing and retrieving large amounts of data accurately and quickly. An early such system was IBM 's Information Management System (IMS), which
6399-503: Was able to handle the processing of more data. Scholarly articles began to be published from different organizations. Looking at early computing, Alan Turing , J. Presper Eckert , and John Mauchly were considered some of the major pioneers of computer technology in the mid-1900s. Giving them such credit for their developments, most of their efforts were focused on designing the first digital computer. Along with that, topics such as artificial intelligence began to be brought up as Turing
6480-496: Was beginning to question such technology of the time period. Devices have been used to aid computation for thousands of years, probably initially in the form of a tally stick . The Antikythera mechanism , dating from about the beginning of the first century BC, is generally considered the earliest known mechanical analog computer , and the earliest known geared mechanism. Comparable geared devices did not emerge in Europe until
6561-468: Was the Manchester Baby , which ran its first program on 21 June 1948. The development of transistors in the late 1940s at Bell Laboratories allowed a new generation of computers to be designed with greatly reduced power consumption. The first commercially available stored-program computer, the Ferranti Mark I , contained 4050 valves and had a power consumption of 25 kilowatts. By comparison,
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