What is the UNIX Shell?
The UNIX shell is a command-line interface, similar in some ways to the old DOS prompt on the PC platform. It is much more powerful, customizable, and easy to use however. In addition to providing a command-line interface to the operating system, the shell also provides a programming language. Shell programs (also commonly called shell scripts) are collections of commands listed one after another inside of a text file. Creating shell scripts provides a simple way to automate repetitive tasks or generate various reports, among a myriad of other possibilities. For simple tasks like program and file management, there is often a choice between using the GUI or the shell to accomplish the same thing. In general, becoming familiar with the shell will make you more productive and efficient. Relying on the GUI is slower, but may require less effort for novices. But even in the latter case it will at some point be necessary to use the shell for something that is not readily available in the GUI
