@Ownix - You have that slightly reversed.
You can think of Albums as being containers for Galleries; and Galleries as containers for images.
Albums can also contain other Albums as well, so you can create a structured display of your images.
Let's use a food example (since I'm getting hungry):
- Breakfast (sub-album)
-- Eggs (sub-sub-album)
--> Scrambled (gallery)
-> Juice (gallery)
- Lunch (sub-album)
> Snacks (gallery)
You can arrange these via Gallery > Manage Albums ... or you can also do this via the ATP under its Manage Albums tab.