World Quest is a feature in coming Legion, similar with the rewards quest in Diablo 3.  Players can find the quest location on the zone map.
World Quest is different from the daily quests of the previous patch. It has its features:
1. There is no NPC to give or deliver a World Quest. They are automatically accepted when you approach the quest location. The quest does give you rewards at the moment you complete it.
2. Different kinds of World Quest include a variety of gaming experiences like killing rare elites or World boss,  Pet Battle, Field PVP quest, Dungeon Quest and professional quest(It is the main way to gain the Blood of Sargeras for crafting profession). No matter you are an experienced player or amateur player, PVP or PVE players, you can find the corresponding world quest.
3. World Quest is different from the daily quest of repeated refreshes every day. Some of the quests last for three days. Some quests rotate every three hours. You will see different quests when you open the map each time.
Players can be active the World Quest when character upgrades to lvl110, and the five faction reputations reach to friendly or higher. There are many different kinds of reward in World Quest, including Artifact Power, order Resource, Gears, Pets, Reputation Rewards, Blood of Sargeras and so on. However, the gears level of quest rewards will upgrade with the character's level upgrades.
Compared to the previous patch quests,  the World Quest have a lot more surprise and fun. You can obtain achievements by completing some different quests and a certain number of quests. But it will be a great challenge for 10,000 World Quests Completed, takes about one year to complete 27 World Quests every day. Maybe you will finish this achievement until the New patch 8.0.