1. What does it mean to precompile files? What does this have to do with Coffeescript and Sass files? Does it only have to do with Coffeescript and Sass files?
Precompiling asset files is a way to help browsers make fewer requests to your webserver to display items on your page. Precompiling is done in Rails via the asset pipeline.
Precompiling consists of 3 tasks: concatenating assets, minifying assets, and providing a way to access those assets in other languages.
CoffeeScript and SASS are JavaScript and CSS frameworks that help with the styling and user experience of your app. In particular, CoffeeScript is a way to write JavaScript with Rubyish syntax. In a production environment, it helps with speed and efficiency to concatenate them, which means combining all the files in which they appear into one master file for each language for the server to reference as a block. The asset pipeline also minifies them, which means removing whitespace and comments, as well as transforming them into a