Trash (トラッシュ Torasshu) is the place to put cards that are no longer used. All cards from the Charge that are used to perform Ignition and Event cards that has been used goes here. Card abilities or effects like Void Bringer may also put a card from its original location into Trash.
Card abilities or effects may interact with the cards in the Trash, either by looking for the card information in Trash or by directly manipulating the cards (e.g. move it from Trash to another location).