is where you will find the documentation we have.
Edit Categories is where you create your category structure.
Personal Albums are the albums people create using the Album Admin link in the menu when they are logged in. Members control their own albums.
Private Galleries are those which have a password applied to them and they do not appear anywhere and require a link to be accessed.
Overall, albums refer to something a user creates and galleries/categories apply to what the admin creates. Albums can be assigned to categories (if enabled) to give users the opportunity to create albums and associate them with public galleries to increase visibility.