# Shell

> > In computing, a shell is a computer program that exposes an OS's services to a human user or other programs. In general, operating system shells use either a CLI or GUI, depending on a computer's role and particular operation. It is named a shell because it is the outermost layer around the operating system.[^1]

> In computing, a shell is a [computer program](https://wiki.g15e.com/pages/Software.txt) that exposes an <OS>'s services to a human user or other programs. In general, operating system shells use either a <CLI> or <GUI>, depending on a computer's role and particular operation. It is named a shell because it is the outermost layer around the operating system.[^1]

## Footnotes

[^1]: https://en.wikipedia.org/wiki/Shell_(computing)