Galleries are groupings of Pages. Every member has at least one Gallery that is considered the default Gallery. You can have multiple Galleries if you decide that you want to segment your work. Common Galleries divide work by creative field (Illustration, Graphic Design, etc.), Year, or even type (Client Work, Personal Work, etc).
Gallery pages contain Page Covers for each subpage within the Galley. When clicked on, the respective subpage will open.