It preprocesses, minifies, and concatenates your assets.
What are assets?
What is preprocessing?
What is concatenating?
What is minifying?
Why should I care?
(... and why should I care?)
From the docs.
http://guides.rubyonrails.org/asset_pipeline.html
1. Preprocessing Files
<%= ERB %>
2. Concatenate Files
I think it's kinda like concatenating strings...
but with files.
3. Minify or compress
Remove returns and white spaces
It's managed in the Manifest File
Using Directives
By Eddie G