MooTools is one of the few JavaScript frameworks that come in different components; it has a very modular design—it is divided into several interdependent parts. Because of its modularity, we're able to pick and choose which parts of MooTools we want. However, if you have a project that doesn't use all of the MooTools components, then it's a good practice to only include the components that you need to reduce page weight and improve response times.

MooTools is organized into two major parts: the MooTools Core and MooTools More (plugins that extend MooTools). Let's take a look at these two components.