With release of World of Warcraft Patch 8.2, the heroes of Azeroth will be able to upgrade their Hearts of Azeroth and get a new, more involved progression system, which will be introduced by a line of introductory quests from Magni the Bronzebeard and MOTHER. You will have to return to the Chamber of Heart in Silithus, and you will be able to access new abilities with the Heart Forge.
You still have to level up your Heart of Azeroth via World Quests and objectives, but now instead of unlocking Azerite Traits, you’ll have:
1) Major slot for Essence – it will be the main slot where you’ll be able to customize your newly unlocked Azerite abilities. It is unlocked right after the introductory questline is completed;
2) Two Minor slots for Essences – those will be passive abilities that enhance your basic stats or apply some positive buffs to you or your party during battle. They are unlocked at Levels 55 and 65;
There are also bonus nodes at Heart of Azeroth Levels 52, 57, 62, and 67, each of them grants a +3% Stamina boost, thus +12% Stamina total when all nodes are unlocked. Essences in Major slot will grant you a new ability and a passive effect, depending on a chosen essence. Essences placed in minor slot will grant you only passive effects, depending on your role.
All essences have four ranks; each of them can be obtained by completing a certain objective in the game. Those objectives can be World and normal quests, Follower missions, drops from bosses in the dungeons and the new raid Eternal Palace. With each rank, the ability of chosen essence becomes more potent and powerful, besides the Legendary Rank 4: it only adds a new cosmetic effect to the ability. That’s why you should consider buying Eternal Palace Run: to benefit from a new system as much as possible. You can choose any new raid service on THIS page.
You can quickly swap Essences to those you need any time the same way as changing talents: make sure you are in a resting area or have a Tome of Tranquil Mind and open Heart of Azeroth with Shift+Right Mouse Button.