Quest

A Quest is a task or duty, sometimes called a mission, in which the player must accomplish a set of objectives, often used by role-playing games to advance the story. Upon completing the quest, the player may receive a reward, or may simply progress to the next part of the story.

A side quest is an optional quest which the player does not need to undergo in order to beat the game or progress the story. Side quests generally serve to provide the player with extra currency or experience, or more powerful items or equipment.