Content Types are the heart and soul of Sense/Net 6.0. They are the structured entities you create and manage in the backend and then somehow display on your portal. Everything you see in the Content Explorer is a Content Type - all the files and even the folders!
A content type is a reusable set of fields you want to apply to certain contents.
When you build a site the first thing you bump into is a Content Type. For example if you want to run a news site the first thing you will have to do - before being able to start off with any kind of designing or programming - is to define what an article will contain. In other words: to define its Content Type. Lets say you decide that an Article needs to have an author, title, abstract, text, and related articles. You will have to create this Content Type. From this time on you will be able to start creating and managing these articles in the backend of your portal via the Content Explorer. And only after that will you be able to create Content Views to display these articles on your website, in the layout(s) you prefer.