Single Cards and Big Picture Cards
Single Cards fill single slots in the set while Big Picture cards fill slots within a larger Picture. Complete the Big Picture to win the Big Picture Prize. 
A Single Card
A Big Picture
Single and Big Picture Cards comprise Sets, and the Sets comprise the Album. You can win a prize by collecting all cards in a Big Picture, all cards in a Set, and all cards in an Album.  Collect all cards in the Album for the HUGE Album prize. The current Album will run for a limited time before it expires. But if you do finish the Album before it expires, you can complete the Album again for even bigger rewards!
Inside the Album
Inside a Set