To Minify a file

Minification in code scripts takes out the white space and unesscesary characters, so that the file takes up less space. This can accelerate load time of your web pages. When using javascript plugins it is best practice to use the minified versions.

For Example:

Boostrap css file size is 143 KB and when minified it shrinks to 117 KB , 22% reduction.

The origins can be trace back to 2001 when JSMin was introduced by Douglas Crawford

Crockford, Douglas (11 September 2001). "JSMin: The JavaScript Minifier". Crockford.com. Self-published. Archived from the original on 5 April 2002.