Code minification (also called code minimization or code compression) is the process of removing all unnecessary characters from the source code. This includes removing all unwanted white space characters, new line characters, comments, etc. Code minification does not affect the functionality of the source code. It however, improves load time (and your web app’s performance) because the size of the file to be downloaded now reduces.
Bonus tool (to find which minification tool works best for you):
It shows aggregated statistics on the general level of compression in four of the tools covered above (namely JSMin, Dojo ShrinkSafe, YUI Compressor and Packer).
Which is your favorite minification tool? Add it in the comment section below.