A graphical user interface (GUI, pronounced "gooey") is a computer environment that simplifies the user's interaction with the computer by representing programs, commands, files, and other options as visual elements, such as icons, pull-down menus, buttons, scroll bars, windows, and dialog boxes. By selecting one of these graphical elements, through either use of a mouse or a selection from a menu, the user can initiate different activities, such as starting a program or printing a document. Prior to the introduction of GUI environments, most interactive user interface programs were text oriented and required the user to learn a set of often complex commands that could be unique to a given program. The first GUI was developed in the 1970s by Xerox Corporation, although GUIs did not become popular until the 1980s with the emergence of the Apple Macintosh computer. Today, the most familiar GUI interfaces are Apple Computer's Macintosh and Microsoft Corporation's Windows operating systems.
Computer software applications, such as word processing and spreadsheet packages, typically use the set of GUI elements built into the operating system and then add other elements of their own. The advantage of the GUI element of any software program is that it provides a standard method for performing a given task (i.e., copying a file, formatting text, printing a document) each time the user requests that option, rather than creating a set of commands unique to each potential request. Many GUI elements are standard across all packages built on the same operating system, so once a user is familiar with the GUI elements of one package, it is easier to then work in other packages.
Generally, because of their GUI elements, any two programs—even from different developers—that are built on the same operating system are able to share data, thereby saving a user from having to rekey the same information for use in different programs. For example, a user can copy a graph created in a spreadsheet package and place, or "paste," it into a word processing document. GUI interfaces also typically offer more than one method for initiating a particular action. For example, to print a document from a program within the Windows environment, a user can select the "Print" option from the "File" menu, click the printer icon, or, as an alternative, use the keyboard shortcut of holding down the Ctrl key and pressing the letter "P." A user can then employ the option that feels most comfortable to him or her across all Windows programs.
The GUI interface has also been instrumental in making the World Wide Web easily accessible to individuals through the use of the use of GUI-based "browser" programs. Netscape Navigator, Internet Explorer, and similar programs enable a user to access and search the web using the familiar GUI format.