A quest is a separate and closed part of the game, usually motivated by story, setting a character (or group of characters) controlled by the player with a specific task to be performed. Tasks can be divided into mandatory, related to the main plot threads, and side tasks, the execution of which is not necessary, although may have specific consequences in the game world (e.g. obtaining a valuable reward, changing the hero’s reputation, accessing new locations).
Most often, quests are commissioned by NPCs who explain their causes, purpose, and often provide information about where, how to complete and rewards. Individual quests can be related to each other, leading to each other or mutually exclusive.
A reward is always awarded for successfully completing quests, usually depending on the degree of complexity and the challenge they pose to the player. In general, the heroes can gain a certain amount of experience points, get rich or gain new allies.