Originally Posted by DragonflyBlue
Tanking is pulling one out of a mob to attack at a time, right?
My main is a druid tank.
A 'tank' is essentially a meat shield. They generally have high armor class, high hit points, and a fair amount of dodge/block/parry (unless you're a druid like me, and you just get dodge because we can't carry shields).
Basic game mechanics:
DPS classes (DPS = damage per second) - these classes do large amounts of damage, but tend to have low hit points, low armor, and limited survival skills for surviving hard hitting opponents. Rogues, mages, warlocks, enhancement shaman, cat druids, shadow priests, and hunters are the most prominent dps classes. However there are a few arms/fury warriors who dps as well as retribution paladins - though generally not as effectively as the prominent dps classes.
Tanking classes - these classes have high armor and hit points, but generally don't do a lot of damage. Their attacks while generally weak, generate a high amount of threat and keep mobs focused on them. Warriors, feral druids, and paladins are best suited for tanking.
Healing classes - Priests, shaman, resto druids, and paladins.
Basically the way it works is, tanks absorb damage and keep monsters busy while the rest of the group (besides the healer(s)) 'burn him down' - damage him immensely so he will die quickly. In most group situations, the healer's primary job is to keep the tank healed.
CC = crowd control. A crowd control ability is essentially a way to keep a mob occupied until it can be tanked/dps'd. Some examples include mage's sheep ability which is a polymorph that turns the mob into a sheep for a period of time, and a rogue's sap ability which stuns a humanoid target for a period of time. The best kinds of CC are renewable - meaning that they have a short cooldown (preferrably shorter than their durration with no diminishing returns) and can be cast in battle.
In Kara (which is an expansive, lvl 70, 10 person dungeon) and in most heroics, I play the role of 'off-tank', which can also be considered a renewable CC. I keep mobs busy until they can be dps'd. (I'm also an off-healer and a dps addition, but that's a whole separate post!)
Another term you're likely to hear in an instance group is 'kite' - which means to keep a mob following you, outside of melee range but within ranged attack while inflicting enough damage to keep him fixated on you. Hunters generally kite well (if they know what they're doing).
Making more sense? Have you done an instance with a group yet? It will likely make more sense once you have...