In the Elder Scrolls Online – A Tank is someone who is the heavily armoured shell of a group, the first one into battle and the front-line of combat to protect and defend everyone else against any threat.
A Tanks main job is to aggro and control enemy targets forcing them to attack you and ensure as little damage as possible is passed onto Damage Dealers and Healers. Once aggro is achieved the next task of the Tank is to position enemies safely where allies are as protected as possible to perform their respective roles. As a Tank it is vital to learn fights quickly and efficiently, know mechanics and tactics for each fight as you are the frontline and you will deal with mechanics more than most other roles in a group. Tanks in ESO, similar to the military vehicle, need a very strong defence and good battlefield manoeuvrability: You take a lot of damage as a Tank so the priority is to boost your Max Health and Resistances so you are able to deal with all incoming damage.
The biggest obstacles for a Tank are self-sustaining and survivability. Tanks usually aim for a high Magicka Recovery stat to help with in combat abilities. Stamina sustain can be difficult, when you block – you lose Stamina and Stamina cannot be regained through regeneration while holding Block. With good sustain, you’ll be able to heal yourself if needed and surviving becomes a lot easier, but experience is key to surviving and learning all areas of your class, race, role and each particular fight is vital.
Once you have mastered the basics of Tanking, you will be expected to support your group by setting up in a particular way. This is where you begin to help your group with certain buffs and gear sets, which increase the group damage output (or survivability and sustain) and also begin using further debuff skills and sets which increase the damage your enemy targets take. The reason why buffing and debuffing is important for the Tank is because you are always on the front-line and close to the enemy so it is far easier for a Tank to maintain certain buffs and debuff. Also, the more damage your group can do, the quicker fights will end which benefits everyone in a group especially a Tank who is having to balance sustain, fight management and more.