Quests are missions or tasks given to you, that when completed, you will be rewarded with stats, items or allowing you to follow-up other related quests. Some of them are repeatable, some with time limitations and most of them are only allowed to do once.

Once you started a quest, it is automatically recorded in your quest book. You can view it's current and completed details by clicking on the game menu.

Try to talk to as many NPCs as possible during your journey to take advantage of as many quests as possible!