This version of Foundation includes smart defaults and doesn't require Sass or any other tools. You would use this to build on top of Foundation with vanilla CSS.
You can customize your build of Foundation below to include or remove certain elements, as well as to define the size of columns, colors, font size and more. Sass Foundation is built using SCSS, and you can work with it in the same way.
To get Foundation using Sass, check out the instructions on the Install documentation page.