In computing, a shell provides an interface for a user to interact with the computer at a fairly basic "system" level, as opposed to interaction with an application program. Most commonly this involves typing commands and receiving output as line-by-line text (a command-line interface), though it can also be said to apply to manipulation of files and system objects through graphical user interfaces with windows, menus, and pointing-device cursors to touch interfaces and voice-driven interfaces.
The command-line shell is used in a number of ways, even though modern computer systems all use a Graphic User Interface for most application programs. Every major computer system has some way to access the shell. In Windows, for example, it can be accessed through the Command Prompt or "DOS Prompt". It is sometimes put to use by the operator for maintenance or advanced operations, though some people use it very widely. Files can also be created in some systems to give the shell a list of commands to execute, and it can be used for a wide variety of things. In Windows, this would be called a "batch file" or "command file", while it is generally called a "shell script" in Unix or Linux. The shell is also openly used by some program compilers.
- Bash, the Bourne-Again SHell, sh.
- Program Manager
- Presentation Manager
- The Apple Macintosh Finder
- Google Chrome
- Apple Computer MacOS for Apple Macintosh
- Apple iOS for iPhone-iPod-iPad
- Microsoft Windows Phone with Windows 8