Albums are a way to obtain different rewards by playing any game mode.

 

Albums are composed of sets, each set has a number of sticker cards that help you fill a set.

 

When a set is completed you obtain a prize for the completion.

 

If you complete all the sets, you obtain the "Grand Prize".

To unlock Sticker Albums and Packs, reach level 10. Any Sticker Packs you win before level 10 will be saved in your reward inbox, accessible through the trophy icon on the top bar of the Home Lobby.
Visit the Collections tab at level 10 by clicking the album on the bottom left of the home lobby to learn more about Sticker albums.