Install

$ gem install sass
$ sass -v
Sass 3.4.23 (Selective Steve)

Partial Sass files

A partial is simply a Sass file named with a leading underscore. You might name it something like _partial.scss. Sass partials are used with the @import directive.

Sass Command

basic

$ sass style.scss:style.css

with watch option

$ sass --watch style:scss:style:css
$ sass --watch main.scss:main.css

Other

.map file

The .map file is a reverse map for the resulting CSS file, showing where each declaration came from in their original SCSS file. They are used be tools like Chrome’s DevTools when you are viewing the resulting web page. https://teamtreehouse.com/community/when-i-type-sass-watch-it-creates-a-maincssmap-file-not-sure-what-that-is