NPC stands for non-player character. It refers to a character controlled by the game rather than by a human player.
What NPCs do
NPCs can give quests, sell items, provide story information, fight the player, join the player's party, guard areas, or simply make a world feel alive.
NPC versus player character
A player character is controlled by the person playing the game. An NPC follows scripts, artificial intelligence, schedules, dialogue trees, or other game systems.
NPCs are especially important in RPGs, open-world games, simulations, and story-driven adventures.