What is combat damage in Magic: The Gathering (MTG)?

Combat damage in Magic: The Gathering (MTG) is the amount of damage dealt by creatures during the combat phase of the game. When a creature attacks and is not blocked, it deals its power in damage to the defending player or planeswalker. If a creature is blocked, it deals damage to the blocking creature, and vice versa. This damage can be prevented or modified by various cards and abilities in the game.