Although we've downloaded the source code version of Bootstrap, it's not one you would use by default.

Huh? I hear you ask. You'd be quite right to do so—after all, what's the point of downloading something you aren't going to use, right…? Well, we will make use of this later in the chapter; for now, it is enough to know that this contains all of the mixins that make up Bootstrap styles and that these can easily be customized at a later date.

For now, we will use the compiled version. In the Building a more realistic site section later in the chapter, we'll see the effects of what happens when we access the Bootstrap mixin file directly.

Let's change track and take a look at what's required to add Bootstrap to your site: