CSS preprocessing allows you to write shortcode, functions, variables, and other time-saving methods for building up your website CSS.
The preferred tool on campus for CSS preprocessing is Sass.
Sass is an extension of the CSS framework that is already in wide usage across the web. However, Sass provides scripting capabilities to make writing CSS easier. Sass compiles Sass commands, variables, and references into cut-and-dry CSS that can be interpreted by websites.
Sass-written CSS looks very similar to the CSS you already know, with a few new features.