There are four primary types of cards: One-Shots, Ongoings, Equipment, and Targets.
One-shots are played, have some sort of immediate effect, and then go to the trash.
Ongoing and Equipment cards work the same, in that they come into play and stay in play, having some sort of ongoing effect or changing the way a character works. These cards can also be Limited, which merely means only one copy of that specific card can be in play at a time.
Targets are anything with HP. When a target is reduced to 0 or fewer HP, it is destroyed and goes to the Trash.