You are likely wondering how these .scss files are getting converted to the app.css file, and it is a great question and there are multiple ways to convert your .scss files to .css files. There are a bunch of applications that will handle it for you and they are listed and updated on the official Sass install page at http://sass-lang.com/install. In Foundation with Sass, Zurb uses something called Grunt to compile your Sass automatically when you hit save. You, of course, have to tell Grunt to check your Sass folder for changes on save, but we will cover that in a while. Let's cover what Grunt is first. Grunt is a JavaScript Task Runner and the project can be viewed at http://gruntjs.com/. What is a JavaScript Task Runner? Simply put, it automates repetitive tasks for you. So, in our case, Grunt watches our SCSS folder and whenever we make a change to one of the files in that folder and hit save, Grunt puts all the files in the SCSS folder into one file, minifies...