Each composition can contain a number of decks, which you can use to manage audio-visual clips and sources.
Decks are accessed through the set of buttons just below the clip layers (above the BPM bar). Each deck has a name. When you select a deck, all of the clips in the deck are displayed in their layers.
A new deck can be created by using the Deck > New or Deck > Insert menu options. The New option adds the new deck to the end of the list while the Insert option adds it to the left of the currently selected deck.
You can also duplicate a deck.
Closing a deck will remove a deck from the interface, but keep its contents intact and it will remain part of the composition. It will remain closed until you open it again.
Clearing a deck removes all its contents, but keeps the empty deck open. Removing a deck will delete it in its entirety.
You can rename a deck by double-clicking its name.