The Simple Starter Kit gives you a bare-bones website that introduces you to a set of well-defined conventions for building an Umbraco website.
The Simple website is very basic in form and provided without any design or functionality - unless you add a Skin, of course. By installing the Simple Starter Kit, you'll begin with a minimal site built on best practices. You'll also enjoy the benefits of speaking the same "language" as the rest of the Umbraco community by using common properties and naming conventions.
Now that you know what the Simple site is, it is time to get started using Umbraco.