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93-524: The taskbar is an exemplar of a category of always-visible graphical user interface elements that provide access to fundamental operating system functions and information. At the time of its introduction in 1995, the taskbar was unique among such elements because it provided the user with a means of switching between running programs through a single click of the pointing device . Since the introduction of Windows 95, other operating systems have incorporated graphical user interface elements that closely resemble

186-539: A hotspot located in the bottom-left corner of the screen replaced the Start button, although this change was reverted in Windows 8.1 and Windows Server 2012 R2 . The Windows 95 taskbar buttons evolved from an earlier task-switching design by Daniel Oran, a program manager at Microsoft, that featured file-folder-like tabs across the top of the screen, similar to those that later appeared in web browsers . For this reason,

279-428: A system call to perform a block I/O write operation, then the system call might execute the following instructions: While the writing takes place, the operating system will context switch to other processes as normal. When the device finishes writing, the device will interrupt the currently running process by asserting an interrupt request . The device will also place an integer onto the data bus. Upon accepting

372-615: A bar across the top of the screen with an Activities button on the left, a clock in the centre, and a notification area on the right. GNOME Shell does not contain a traditional taskbar; users can manage windows, virtual desktops, and launch applications from either a "Dash" on the side of the screen, or by searching from Activities Overview, which is displayed by clicking on the Activities button. GNOME 3.8 introduces Classic Mode, which re-implements certain aspects of GNOME 2's desktop as an alternate desktop environment that can be selected at

465-446: A border of pixels surrounding the Start button which did not activate the menu, allowing the menu to be activated by clicking directly in the corner of the screen. Icons in the notification area could now be hidden to save space and revealed with the arrow button. For Windows Vista , the taskbar remained functionally the same but received a visual overhaul to align the new Windows Aero design language, introducing transparency effects to

558-516: A clock and notification area, while the bottom panel contains buttons for navigating between virtual desktops , the window list proper, and a button which minimizes all windows (similarly to Windows' Show desktop button). The contents of panels are handled by widgets called panel applets, which can consist of application shortcuts, search tools, or other tools. The contents of the panels can be moved, removed, or configured in other ways. In GNOME 3, panels are replaced by GNOME Shell , which consists of

651-645: A computer even if they are not compatible with the base operating system. A library operating system (libOS) is one in which the services that a typical operating system provides, such as networking, are provided in the form of libraries and composed with a single application and configuration code to construct a unikernel : a specialized (only the absolute necessary pieces of code are extracted from libraries and bound together ), single address space , machine image that can be deployed to cloud or embedded environments. The operating system code and application code are not executed in separated protection domains (there

744-585: A development of MULTICS for a single user. Because UNIX's source code was available, it became the basis of other, incompatible operating systems, of which the most successful were AT&T 's System V and the University of California 's Berkeley Software Distribution (BSD). To increase compatibility, the IEEE released the POSIX standard for operating system application programming interfaces (APIs), which

837-522: A few years, Microsoft gained a dominant position in the browser market for two reasons: it bundled Internet Explorer with its popular Windows operating system and did so as freeware with no restrictions on usage. The market share of Internet Explorer peaked at over 95% in the early 2000s. In 1998, Netscape launched what would become the Mozilla Foundation to create a new browser using the open-source software model. This work evolved into

930-484: A large legal settlement was paid. In the twenty-first century, Windows continues to be popular on personal computers but has less market share of servers. UNIX operating systems, especially Linux, are the most popular on enterprise systems and servers but are also used on mobile devices and many other computer systems. On mobile devices, Symbian OS was dominant at first, being usurped by BlackBerry OS (introduced 2002) and iOS for iPhones (from 2007). Later on,

1023-442: A library with no protection between applications, such as eCos . A hypervisor is an operating system that runs a virtual machine . The virtual machine is unaware that it is an application and operates as if it had its own hardware. Virtual machines can be paused, saved, and resumed, making them useful for operating systems research, development, and debugging. They also enhance portability by enabling applications to be run on

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1116-447: A malformed machine instruction . However, the most common error conditions are division by zero and accessing an invalid memory address . Users can send messages to the kernel to modify the behavior of a currently running process. For example, in the command-line environment , pressing the interrupt character (usually Control-C ) might terminate the currently running process. To generate software interrupts for x86 CPUs,

1209-455: A particular application's memory is stored, or even whether or not it has been allocated yet. In modern operating systems, memory which is accessed less frequently can be temporarily stored on a disk or other media to make that space available for use by other programs. This is called swapping , as an area of memory can be used by multiple programs, and what that memory area contains can be swapped or exchanged on demand. Virtual memory provides

1302-511: A popular category of shareware on these systems. The Dock , as featured in macOS and its predecessor NeXTSTEP , is also a kind of taskbar. The macOS Dock is application-oriented instead of window-oriented. Each running application is represented by one icon in the Dock regardless of how many windows it has on screen. A textual menu can be opened by right-clicking on the dock icon that gives access to an application's windows. Mac OS X 10.2 added

1395-503: A program does not interfere with memory already in use by another program. Since programs time share, each program must have independent access to memory. Cooperative memory management, used by many early operating systems, assumes that all programs make voluntary use of the kernel 's memory manager, and do not exceed their allocated memory. This system of memory management is almost never seen any more, since programs often contain bugs which can cause them to exceed their allocated memory. If

1488-408: A program fails, it may cause memory used by one or more other programs to be affected or overwritten. Malicious programs or viruses may purposefully alter another program's memory, or may affect the operation of the operating system itself. With cooperative memory management, it takes only one misbehaved program to crash the system. Memory protection enables the kernel to limit a process' access to

1581-440: A program tries to access memory that is not accessible memory, but nonetheless has been allocated to it, the kernel is interrupted (see § Memory management ) . This kind of interrupt is typically a page fault . When the kernel detects a page fault it generally adjusts the virtual memory range of the program which triggered it, granting it access to the memory requested. This gives the kernel discretionary power over where

1674-457: A range of devices, including desktops , laptops , tablets , and smartphones . By 2020, an estimated 4.9 billion people had used a browser. The most-used browser is Google Chrome , with a 67% global market share on all devices, followed by Safari with 18%. A web browser is not the same thing as a search engine , though the two are often confused. A search engine is a website that provides links to other websites. However, to connect to

1767-470: A significant amount of CPU time. Direct memory access (DMA) is an architecture feature to allow devices to bypass the CPU and access main memory directly. (Separate from the architecture, a device may perform direct memory access to and from main memory either directly or via a bus.) When a computer user types a key on the keyboard, typically the character appears immediately on the screen. Likewise, when

1860-402: A specific moment in time. Hard real-time systems require exact timing and are common in manufacturing , avionics , military, and other similar uses. With soft real-time systems, the occasional missed event is acceptable; this category often includes audio or multimedia systems, as well as smartphones. In order for hard real-time systems be sufficiently exact in their timing, often they are just

1953-403: A taskbar onscreen by default. Application switching prior to Mac OS 8.5 was done by clicking on an application's window or via a pull-down menu at the right end of the menu bar . Prior to version 8.5 the menu's title was the icon of the foreground application. Version 8.5 introduced the ability to optionally also display the application name and to "tear off" the menu by dragging the title with

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2046-417: A user moves a mouse , the cursor immediately moves across the screen. Each keystroke and mouse movement generates an interrupt called Interrupt-driven I/O . An interrupt-driven I/O occurs when a process causes an interrupt for every character or word transmitted. Devices such as hard disk drives , solid-state drives , and magnetic tape drives can transfer data at a rate high enough that interrupting

2139-453: A variation of the classic reader/writer problem . The writer receives a pipe from the shell for its output to be sent to the reader's input stream. The command-line syntax is alpha | bravo . alpha will write to the pipe when its computation is ready and then sleep in the wait queue. bravo will then be moved to the ready queue and soon will read from its input stream. The kernel will generate software interrupts to coordinate

2232-408: A website's server and display its web pages, a user must have a web browser installed. In some technical contexts, browsers are referred to as user agents . The purpose of a web browser is to fetch content and display it on the user's device. This process begins when the user inputs a Uniform Resource Locator (URL), such as https://en.wikipedia.org/ , into the browser. Virtually all URLs on

2325-562: Is remote direct memory access , which enables each CPU to access memory belonging to other CPUs. Multicomputer operating systems often support remote procedure calls where a CPU can call a procedure on another CPU, or distributed shared memory , in which the operating system uses virtualization to generate shared memory that does not physically exist. A distributed system is a group of distinct, networked computers—each of which might have their own operating system and file system. Unlike multicomputers, they may be dispersed anywhere in

2418-428: Is system software that manages computer hardware and software resources, and provides common services for computer programs . Time-sharing operating systems schedule tasks for efficient use of the system and may also include accounting software for cost allocation of processor time , mass storage , peripherals, and other resources. For hardware functions such as input and output and memory allocation ,

2511-484: Is a change away from the currently running process. Similarly, both hardware and software interrupts execute an interrupt service routine . Software interrupts may be normally occurring events. It is expected that a time slice will occur, so the kernel will have to perform a context switch . A computer program may set a timer to go off after a few seconds in case too much data causes an algorithm to take too long. Software interrupts may be error conditions, such as

2604-403: Is also a notification area, which includes interactive icons that display real-time information about the computer system and some of the running programs. With the rapid evolution of operating systems and graphical user interfaces, items that are native to each operating system have been included in the various designs. Windows 1.0 , released in 1985, features a horizontal bar located at

2697-422: Is difficult to define, but has been called "the layer of software that manages a computer's resources for its users and their applications ". Operating systems include the software that is always running, called a kernel —but can include other software as well. The two other types of programs that can run on a computer are system programs —which are associated with the operating system, but may not be part of

2790-443: Is only a single application running, at least conceptually, so there is no need to prevent interference between applications) and OS services are accessed via simple library calls (potentially inlining them based on compiler thresholds), without the usual overhead of context switches , in a way similarly to embedded and real-time OSes. Note that this overhead is not negligible: to the direct cost of mode switching it's necessary to add

2883-499: Is supported by most UNIX systems. MINIX was a stripped-down version of UNIX, developed in 1987 for educational uses, that inspired the commercially available, free software Linux . Since 2008, MINIX is used in controllers of most Intel microchips , while Linux is widespread in data centers and Android smartphones. The invention of large scale integration enabled the production of personal computers (initially called microcomputers ) from around 1980. For around five years,

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2976-473: Is that they do not load user-installed software. Consequently, they do not need protection between different applications, enabling simpler designs. Very small operating systems might run in less than 10 kilobytes , and the smallest are for smart cards . Examples include Embedded Linux , QNX , VxWorks , and the extra-small systems RIOT and TinyOS . A real-time operating system is an operating system that guarantees to process events or data by or at

3069-435: Is the part of the operating system that provides protection between different applications and users. This protection is key to improving reliability by keeping errors isolated to one program, as well as security by limiting the power of malicious software and protecting private data, and ensuring that one program cannot monopolize the computer's resources. Most operating systems have two modes of operation: in user mode ,

3162-414: Is therefore called gnome-panel ). By default, GNOME 2 usually contains two full-width panels at the top and bottom of the screen. The top panel usually contains navigation menus labeled Applications , Places , and System in that order. These menus hold links to common applications, areas of the file system, and system preferences and administration utilities, respectively. The top panel usually contains

3255-483: The Arthur operating system from Acorn Computers . It is called the icon bar and remains an essential part of Arthur's succeeding RISC OS operating system. The icon bar holds icons which represent mounted disc drives and RAM discs, running applications and system utilities. These icons have their own context-sensitive menus and support drag and drop behaviour. AmigaOS featured various third party implementations of

3348-542: The CP/M (Control Program for Microcomputers) was the most popular operating system for microcomputers. Later, IBM bought the DOS (Disk Operating System) from Microsoft . After modifications requested by IBM, the resulting system was called MS-DOS (MicroSoft Disk Operating System) and was widely used on IBM microcomputers. Later versions increased their sophistication, in part by borrowing features from UNIX. Apple 's Macintosh

3441-558: The Firefox browser, first released by Mozilla in 2004. Firefox's market share peaked at 32% in 2010. Apple released its Safari browser in 2003; it remains the dominant browser on Apple devices, though it did not become popular elsewhere. Google debuted its Chrome browser in 2008, which steadily took market share from Internet Explorer and became the most popular browser in 2012. Chrome has remained dominant ever since. By 2015, Microsoft replaced Internet Explorer with Edge for

3534-504: The INT assembly language instruction is available. The syntax is INT X , where X is the offset number (in hexadecimal format) to the interrupt vector table . To generate software interrupts in Unix-like operating systems, the kill(pid,signum) system call will send a signal to another process. pid is the process identifier of the receiving process. signum is

3627-428: The Windows 10 release. Since the early 2000s, browsers have greatly expanded their HTML , CSS , JavaScript , and multimedia capabilities. One reason has been to enable more sophisticated websites, such as web apps . Another factor is the significant increase of broadband connectivity in many parts of the world, enabling people to access data-intensive content, such as streaming HD video on YouTube , that

3720-498: The personal computer market, as of September 2024 , Microsoft Windows holds a dominant market share of around 73%. macOS by Apple Inc. is in second place (15%), Linux is in third place (5%), and ChromeOS is in fourth place (2%). In the mobile sector (including smartphones and tablets ), as of September 2023 , Android's share is 68.92%, followed by Apple's iOS and iPadOS with 30.42%, and other operating systems with .66%. Linux distributions are dominant in

3813-420: The transistor in the mid-1950s, mainframes began to be built. These still needed professional operators who manually do what a modern operating system would do, such as scheduling programs to run, but mainframes still had rudimentary operating systems such as Fortran Monitor System (FMS) and IBSYS . In the 1960s, IBM introduced the first series of intercompatible computers ( System/360 ). All of them ran

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3906-410: The CPU for every byte or word transferred, and having the CPU transfer the byte or word between the device and memory, would require too much CPU time. Data is, instead, transferred between the device and memory independently of the CPU by hardware such as a channel or a direct memory access controller; an interrupt is delivered only when all the data is transferred. If a computer program executes

3999-474: The CPU to re-enter supervisor mode , placing the kernel in charge. This is called a segmentation violation or Seg-V for short, and since it is both difficult to assign a meaningful result to such an operation, and because it is usually a sign of a misbehaving program, the kernel generally resorts to terminating the offending program, and reports the error. Windows versions 3.1 through ME had some level of memory protection, but programs could easily circumvent

4092-565: The Quick Launch toolbar in certain versions and configurations). In addition to deskbands, Windows supports "Application Desktop Toolbars" (also called "appbands") that supports creating additional toolbars that can dock to any side of the screen, and cannot be overlaid by other applications. Users can add additional toolbars that display the contents of folders. The display for toolbars that represent folder items (such as Links, Desktop and Quick Launch) can be changed to show large icons and

4185-542: The Web start with either http: or https: which means they are retrieved with the Hypertext Transfer Protocol (HTTP). For secure mode (HTTPS), the connection between the browser and web server is encrypted , providing a secure and private data transfer. Web pages usually contain hyperlinks to other pages and resources. Each link contains a URL, and when it is clicked or tapped ,

4278-417: The ability for an application to add items of its own to this menu. Minimized windows also appear in the dock, in the rightmost section, represented by a real-time graphical thumbnail of the window's contents. The trash can is also represented in the Dock, as a universal metaphor for deletion. For example, dragging selected text to the trash should remove the text from the document and create a clipping file in

4371-538: The application program, which then interacts with the user and with hardware devices. However, in some systems an application can request that the operating system execute another application within the same process, either as a subroutine or in a separate thread, e.g., the LINK and ATTACH facilities of OS/360 and successors . An interrupt (also known as an abort , exception , fault , signal , or trap ) provides an efficient way for most operating systems to react to

4464-611: The average person. This, in turn, sparked the Internet boom of the 1990s, when the Web grew at a very rapid rate. The lead developers of Mosaic then founded the Netscape corporation, which released the Mosaic-influenced Netscape Navigator in 1994. Navigator quickly became the most popular browser. Microsoft debuted Internet Explorer in 1995, leading to a browser war with Netscape. Within

4557-424: The bottom of the screen and cannot be moved to the top, left, or right side). Up to and including Windows Server 2008, the taskbar is constrained to single display, although third-party utilities such as UltraMon allow it to span multiple displays. When the taskbar is displayed vertically on versions of Windows prior to Windows Vista, the Start menu button will only display the text "Start" or translated equivalent if

4650-465: The bottom of the screen where running programs reside when minimized (referred to as "iconization" at the time), represented by icons. A window can be minimized by double-clicking its title bar , dragging it onto an empty spot on the bar, or by issuing a command from one of its menus . A minimized window is restored by double-clicking its icon or dragging the icon out of the bar. The bar features multiple slots for icons and expands vertically to provide

4743-401: The browser navigates to the new resource. Most browsers use an internal cache of web page resources to improve loading times for subsequent visits to the same page. The cache can store many items, such as large images, so they do not need to be downloaded from the server again. Cached items are usually only stored for as long as the web server stipulates in its HTTP response messages. During

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4836-453: The computer's memory. Various methods of memory protection exist, including memory segmentation and paging . All methods require some level of hardware support (such as the 80286 MMU), which does not exist in all computers. In both segmentation and paging, certain protected mode registers specify to the CPU what memory address it should allow a running program to access. Attempts to access other addresses trigger an interrupt, which causes

4929-433: The course of browsing, cookies received from various websites are stored by the browser. Some of them contain login credentials or site preferences. However, others are used for tracking user behavior over long periods of time, so browsers typically provide a section in the menu for deleting cookies. Finer-grained management of cookies usually requires a browser extension . The first web browser, called WorldWideWeb ,

5022-471: The details of how interrupt service routines behave vary from operating system to operating system. However, several interrupt functions are common. The architecture and operating system must: A software interrupt is a message to a process that an event has occurred. This contrasts with a hardware interrupt — which is a message to the central processing unit (CPU) that an event has occurred. Software interrupts are similar to hardware interrupts — there

5115-422: The environment. Interrupts cause the central processing unit (CPU) to have a control flow change away from the currently running program to an interrupt handler , also known as an interrupt service routine (ISR). An interrupt service routine may cause the central processing unit (CPU) to have a context switch . The details of how a computer processes an interrupt vary from architecture to architecture, and

5208-410: The hardware checks that the software is only executing legal instructions, whereas the kernel has unrestricted powers and is not subject to these checks. The kernel also manages memory for other processes and controls access to input/output devices. The operating system provides an interface between an application program and the computer hardware, so that an application program can interact with

5301-493: The hardware only by obeying rules and procedures programmed into the operating system. The operating system is also a set of services which simplify development and execution of application programs. Executing an application program typically involves the creation of a process by the operating system kernel , which assigns memory space and other resources, establishes a priority for the process in multi-tasking systems, loads program binary code into memory, and initiates execution of

5394-418: The indirect pollution of important processor structures (like CPU caches , the instruction pipeline , and so on) which affects both user-mode and kernel-mode performance. The first computers in the late 1940s and 1950s were directly programmed either with plugboards or with machine code inputted on media such as punch cards , without programming languages or operating systems. After the introduction of

5487-404: The interrupt request, the operating system will: When the writing process has its time slice expired, the operating system will: With the program counter now reset, the interrupted process will resume its time slice. Among other things, a multiprogramming operating system kernel must be responsible for managing all system memory which is currently in use by the programs. This ensures that

5580-431: The kernel—and applications—all other software. There are three main purposes that an operating system fulfills: With multiprocessors multiple CPUs share memory. A multicomputer or cluster computer has multiple CPUs, each of which has its own memory . Multicomputers were developed because large multiprocessors are difficult to engineer and prohibitively expensive; they are universal in cloud computing because of

5673-411: The login screen. These desktop environments provide their own implementation of a taskbar: Standalone window managers that provide an integrated taskbar include: Programs that offer standalone taskbars for desktop environments or window managers without one include Avant Window Navigator , pypanel, fbpanel, perlpanel, tint2, and others. Operating system An operating system ( OS )

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5766-400: The memory allocated to a different one. Around the same time, teleprinters began to be used as terminals so multiple users could access the computer simultaneously. The operating system MULTICS was intended to allow hundreds of users to access a large computer. Despite its limited adoption, it can be considered the precursor to cloud computing . The UNIX operating system originated as

5859-462: The mouse. The torn off menu was displayed as a palette . The palette window could be configured using AppleScript to appear much like a taskbar, with no title bar and fixed to one edge of the screen. No control panel was provided by Apple to access this functionality, but third-party developers quickly wrote applications that allowed users unfamiliar with AppleScript to customize their application palettes. Third party taskbars such as DragThing were

5952-408: The need to use it. A general protection fault would be produced, indicating a segmentation violation had occurred; however, the system would often crash anyway. The use of virtual memory addressing (such as paging or segmentation) means that the kernel can choose what memory each program may use at any given time, allowing the operating system to use the same memory locations for multiple tasks. If

6045-408: The open-source Android operating system (introduced 2008), with a Linux kernel and a C library ( Bionic ) partially based on BSD code, became most popular. The components of an operating system are designed to ensure that various parts of a computer function cohesively. With the de facto obsoletion of DOS , all user software must interact with the operating system to access hardware. The kernel

6138-420: The operating system acts as an intermediary between programs and the computer hardware, although the application code is usually executed directly by the hardware and frequently makes system calls to an OS function or is interrupted by it. Operating systems are found on many devices that contain a computer – from cellular phones and video game consoles to web servers and supercomputers . In

6231-525: The option to show the application labels and reduce the taskbar height to create a taskbar similar to the design used in Windows Vista. At the right side of the taskbar, the Aero Peak button was added, allowing users to quickly view the contents of the desktop and their widgets by hovering over the button, or minimize all applications by clicking on it. Windows 8 introduced no functional changes to

6324-421: The piping. Signals may be classified into 7 categories. The categories are: Input/output (I/O) devices are slower than the CPU. Therefore, it would slow down the computer if the CPU had to wait for each I/O to finish. Instead, a computer may implement interrupts for I/O completion, avoiding the need for polling or busy waiting. Some computers require an interrupt for each character or word, costing

6417-402: The programmer or the user with the perception that there is a much larger amount of RAM in the computer than is really there. Web browser A web browser is an application for accessing websites . When a user requests a web page from a particular website, the browser retrieves its files from a web server and then displays the page on the user's screen. Browsers are used on

6510-418: The same operating system— OS/360 —which consisted of millions of lines of assembly language that had thousands of bugs . The OS/360 also was the first popular operating system to support multiprogramming , such that the CPU could be put to use on one job while another was waiting on input/output (I/O). Holding multiple jobs in memory necessitated memory partitioning and safeguards against one job accessing

6603-619: The server and supercomputing sectors. Other specialized classes of operating systems (special-purpose operating systems), such as embedded and real-time systems, exist for many applications. Security-focused operating systems also exist. Some operating systems have low system requirements (e.g. light-weight Linux distribution ). Others may have higher system requirements. Some operating systems require installation or may come pre-installed with purchased computers ( OEM -installation), whereas others may run directly from media (i.e. live CD ) or flash memory (i.e. USB stick). An operating system

6696-400: The signal number (in mnemonic format) to be sent. (The abrasive name of kill was chosen because early implementations only terminated the process.) In Unix-like operating systems, signals inform processes of the occurrence of asynchronous events. To communicate asynchronously, interrupts are required. One reason a process needs to asynchronously communicate to another process solves

6789-400: The size of the machine needed. The different CPUs often need to send and receive messages to each other; to ensure good performance, the operating systems for these machines need to minimize this copying of packets . Newer systems are often multiqueue —separating groups of users into separate queues —to reduce the need for packet copying and support more concurrent users. Another technique

6882-530: The taskbar concept, and this inheritance is present also in its successors. For example, AmiDock , born as third-party utility, has then been integrated into AmigaOS 3.9 and AmigaOS 4.0. The AROS operating system has its version of Amistart that is provided with the OS and free to be installed by users, while MorphOS has been equipped with a dock utility just like in AmigaOS or Mac OS X . The default settings for

6975-699: The taskbar in Microsoft Windows place it at the bottom of the screen and includes from left to right the Start menu button , Quick Launch bar , taskbar buttons , and notification area . The Quick Launch toolbar was added with the Windows Desktop Update and is not enabled by default in Windows XP . Windows 7 removed the Quick Launch feature in favor of pinning applications to the taskbar itself. In Windows 8 and Windows Server 2012 ,

7068-430: The taskbar is wide enough to show the full text. However, the edge of the taskbar (in any position) can be dragged to control its height (width for a vertical taskbar); this is especially useful for a vertical taskbar to show window titles next to the window icons. Users can resize the height (or width when displayed vertically) of the taskbar up to half of the display area. To avoid inadvertent resizing or repositioning of

7161-485: The taskbar or have similar features. The designs vary, but generally include a strip along one edge of the screen . Icons or textual descriptions on this strip correspond to open windows . Clicking the icons or text enables the user to easily switch between windows, with the active window often appearing differently from the others on the strip. In some versions of recent operating systems, users can "pin" programs or files to this strip for quick access. In many cases, there

7254-447: The taskbar was originally intended to be at the top of the screen. But the final configuration of Windows 95 put the taskbar at the bottom of the screen, replacing a user interface element called the tray that had been borrowed from Microsoft's Cairo project. Windows 95 OSR 2.5 would add the Quick Launch toolbar. With the release of Windows XP, Microsoft changed the behavior of the taskbar to take advantage of Fitts's law by removing

7347-402: The taskbar would now change when Windows was set to tablet mode, hiding the pinned and running apps and collapsing the search bar into a search icon. It would also show a back button. The Windows taskbar can be modified by users in several ways. The position of the taskbar can be changed to appear on any edge of the primary display (except in Windows 11 , where the taskbar is permanently fixed at

7440-440: The taskbar, Windows XP and later lock the taskbar by default. When unlocked, "grips" are displayed next to the movable elements which allow grabbing with the mouse to move and size. These grips slightly decrease amount of available space in the taskbar. The taskbar as a whole can be hidden until the mouse pointer is moved to the display edge, or has keyboard focus. The Windows 7+ taskbar does not allow pinning any arbitrary folder to

7533-418: The taskbar, and a start button that now slightly overlapped the content displayed above the taskbar. With Windows 7 saw the first major redesign of the taskbar since its introduction with larger application icons, the ability to pin application to the taskbar so that they're shown even if they aren't running, and hiding the application names by default. Quick Launch was also disabled by default. Users still had

7626-477: The taskbar, but replaced the Start button and Aero Peek button with hot corners for desktop users. Tablet users could now use the Charms bar. Windows 8.1 restored the Start button, and with Windows 8.1 Update, it was now possible to see Metro apps on the taskbar and pin them, as well as to access the taskbar while on the Start screen. Windows 10 , version 1507 added various major changes to the taskbar. A search bar

7719-503: The taskbar, it gets pinned instead to the jumplist of a pinned Explorer shortcut, however third party utilities such as Winaero 's Taskbar Pinner can be used to pin any type of shortcut to the taskbar. Other toolbars, known as "Deskbands", may be added to the taskbar. This feature, along with many other taskbar features is currently absent in Windows 11. Windows includes the following deskbands but does not display them by default (except

7812-488: The text for each item. Prior to Windows Vista, the Desktop Toolbars could be dragged off the taskbar and float independently, or docked to a display edge. Windows Vista greatly limited , but did not eliminate the ability to have desktop toolbar not attached to the taskbar. Windows 7 has deprecated the use of Floating Deskbands altogether; they only appear pinned into the taskbar. Classic Mac OS did not display

7905-508: The top four are made from different codebases . Safari , based on Apple 's WebKit code, is the second most popular web browser and is dominant on Apple devices, resulting in an 18% global share. Firefox , in fourth place, with about 3% market share, is based on Mozilla 's code. Both of these codebases are open-source, so a number of small niche browsers are also made from them. The most popular browsers share many features in common. They automatically log users' browsing history , unless

7998-478: The trash. The right side of macOS's Menu bar also typically contains several notification widgets and quick access functions, called Menu extras . In KDE Plasma 5 , taskbar uses Widgets as elements in taskbar. In the update 5.20 (November 2020) they updated the taskbar to look more like Windows 10 by only displaying icons by default and grouping application windows together. GNOME 2 used its own type of taskbar, known as panels (the program responsible for them

8091-473: The user with more rows as more slots are needed. Its color is the same as that of the screen background, which can be customized. Minimized windows can be freely placed in any of the empty slots. Program windows cannot overlap the bar unless maximized. The Start button did not make an appearance in these early implementations of the taskbar, and would be introduced at a much later date with the release of Windows 95 . Another early implementation can be seen in

8184-461: The users turn off their browsing history or use the non-logging private mode . They also allow users to set bookmarks , customize the browser with extensions , and can manage user passwords . Some provide a sync service and web accessibility features. Common user interface (UI) features: While mobile browsers have similar UI features as desktop versions, the limitations of touch screens require mobile UIs to be simpler. The difference

8277-473: The world. Middleware , an additional software layer between the operating system and applications, is often used to improve consistency. Although it functions similarly to an operating system, it is not a true operating system. Embedded operating systems are designed to be used in embedded computer systems , whether they are internet of things objects or not connected to a network. Embedded systems include many household appliances. The distinguishing factor

8370-592: Was created in 1990 by Sir Tim Berners-Lee . He then recruited Nicola Pellow to write the Line Mode Browser , which displayed web pages on dumb terminals . The Mosaic web browser was released in April 1993, and was later credited as the first web browser to find mainstream popularity. Its innovative graphical user interface made the World Wide Web easy to navigate and thus more accessible to

8463-550: Was not possible during the era of dial-up modems . Google Chrome has been the dominant browser since the mid-2010s and currently has a 67% global market share on all devices. The vast majority of its source code comes from Google's open-source Chromium project; this code is also the basis for many other browsers, including Microsoft Edge , currently in third place with about a 5% share, as well as Samsung Internet and Opera in fifth and sixth places respectively with over 2% market share each. The other two browsers in

8556-493: Was now shown by default that could be replaced with a search button or be hidden, when Cortana was available, the search function was replaced with the digital assistant. The Task View button allowed users to quickly view their running apps and desktops. A button to open the Action Center was also added on the left hand side of the clock, before being moved to the right hand side in Windows 10, version 1607 . Additionally,

8649-406: Was the first popular computer to use a graphical user interface (GUI). The GUI proved much more user friendly than the text-only command-line interface earlier operating systems had used. Following the success of Macintosh, MS-DOS was updated with a GUI overlay called Windows . Windows later was rewritten as a stand-alone operating system, borrowing so many features from another ( VAX VMS ) that

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