"Scripts" is a very wide term. You can be speaking of web scripts along the lines of the above mentioned JavaScript or the more advanced PHP, Perl and so on scripts. Or you could mean scripts in system languages and many other types all together.

A script is the code of any given program - be it a program like those you run every day on your computer (an instant messenger, your browser, etc.) or a web page.

So, in turn, you don't "use" scripts in any way unless you are the developer of software for any given purpose.