Player

A player is one of the people in the game.

Starting player
The starting player is the player who has the first turn. undefined

Active player
The active player, also referred to as the attacking player, is the player currently taking their turn. (Compare with all other players in the game, who are nonactive players.) When more than one player have to take actions or make choices, usually the active player goes first (see APNAP). undefined

Non-active player
A nonactive player is any player who is not currently taking their turn. (Compare with the player/players who are currently taking a turn, active players.) When more than one player have to take actions or make choices, usually the active player goes first (see APNAP).

Defending player
During the combat phase of a two-player game, the nonactive player is the defending player; that player and planeswalkers they control may be attacked. undefined undefined In certain multiplayer games, there may be multiple defending player or an opposing Two-Headed Giant.

APNAP
APNAP stands for active player, then non-active player. When an effect lets more than one player do something at the same time, the active player will make and announce all decisions necessary for the action first, then the nonactive player(s) will do the same in turn order, and finally all of the actions will take place simultaneously. undefined undefined

APNAP also applies when the rules (or an effect) require several players to do something that can't all be done at the same time. If multiple triggered abilities are waiting to go on the stack when a player would receive priority, the players will first put their triggered abilities on the stack in APNAP order. Since the stack resolves in reverse order, this means the active player's triggers will resolve last. undefined