Domains are collections of types. When viewing a topic in Freebase, the properties (or facts) are organized by types on the page. For example, see Justin Timberlake or Wait! Wait! Don't Tell me. These types are grouped by domain and each group of types can be collapsed or expanded as you like. You can also easily get to the domain via the link provided.
You may also notice that some types appearing at the bottom of the page are identified as being from user domains. These domains are created by users which distinguishes them from those in the Freebase Commons. Its possible to view the topic through a lense or view that is particular to that domain by clicking on the 'user created view' link. This view will show only the properties associated with types in that domain. In future releases you'll be able to customize this domain-specific view even further.
If you're still working on types in one of your user domains and don't want them to appear on the topic page in this way, you can mark the domain as draft by clicking the 'visibility' link in the domain settings in the upper right-hand corner of the domain page. This will hide the types from that domain on the topic view that people see when they search Freebase. The type will also no longer appear in search and autocomplete.
Note that just because draft domains aren't published doesn't mean you can't share them with others. If you want to view the Justin Timberlake topic with a type from a draft domain, you simply need to navigate to it from the domain page. For example, you could view this domain, follow a link to one of its types, and then view the topic from there. You can see that the properties from this draft type appear in this view. You can always get back to the full view of the topic by clicking on 'full view'.
Your default domain, which Freebase automatically creates and associates with your username when you register, behaves like a permanent draft domain. Here you can experiment with type creation without fear of cluttering up the general Freebase topic view. When you have created new types in your default domain and you want to make them visible to other users via the full topic view, you should create a new domain and move the types into it.
