Features
Site Settings > Features/Permissions

The basic features every site starts with as turned on are Blogging, Categories (Tags), Comments, Image Galleries, Custom Pages, Embedded Media and Code and Five Star ratings.
You can disable any of these features and they will disappear from the site. Or, in some instance, you can enable or disable them from being used just on particular types of content. For example, you can enable five star ratings on blog posts, but not image posts (or vice versa).
All this is accomplished via check boxes.
You can also enable only certain types of users to be able to use your features. Probably the best example is the blog: you can run a blog so only you can contribute as the administrator. But you can also designate that “contributors” can post to the blog, allowing you to run a group blog. You can even designate that “registered users” (or “unregistered visitors”) can contribute, creating a community blog that all your members can write for.
Let’s discuss the definition of these various roles, and how you can assign your specific users different role designations.