107.1.a. This space is where cards are placed when they are killed or discarded, when they finish being executed as spells, when they are moved to the trash as an effect, etc.
107.1.b. Represents cards that have been used or spent.
107.1.c. Each player has a separate trash.
107.1.d. A card owned by a player can never, for any reason, be put into a trash of another player. If it would be, it's put into its owner's trash instead.
107.1.e. The cards in the Trash are unordered. Their sequence does not matter, and they may be reorganized.
107.1.f. The cards in any player's Trash are Public Information. See rule 127. Privacy for more information.