Tank

Noun: Tank
Tanks are well-protected front row party members whose role is to draw the enemy's attention (aggro) and attacks towards themselves as well as absorbing damage. They block their enemy's way and as such serve as meat shields for the spell casters and ranged attackers in the back lines behind them. They usually engage foes with melee or PBAoE attacks.

Warriors are the most common form of tank, having the strongest armor against physical attacks of any profession. Warriors have many skills (especially in the Tactics line) to help minimize damage and hold the enemies' attention. Other professions need to be more creative to mitigate damage and so are less common on the whole.

Warrior Tanks
A tanking warrior will come equipped with defensive tactics to mitigate as much damage as possible. Typically, the warrior will charge the enemy and will focus mostly on engaging the frontline, keeping mobs attention off other characters in the back row. Tanks use shields, stances and, sometimes, secondary profession skills such as Protection Prayers to minimize damage inflicted upon them. They can take quite a long while to kill. Tanks can be used as booby traps using AoE spells that are centered on the caster such as Inferno or Shield of Judgment, but should avoid skills that do damage over time as enemy mobs will run away.

Other Tanks
Some professions, given the right set of skills and proper preparation, can tank for their parties in certain areas. In particular, Rangers, Monks and Elementalists possess in their skill set a number of skills that can be used to make them very resilient to damage. These builds are usually attuned to the monsters in certain explorable areas that do not possess the means to overcome them. When the enemy is highly variable (as is the case in PvP), non-Warrior professions become susceptible to facing counters designed specifically for their means of damage reduction. For example, monks and elementalists relying on enchantments to resist attacks will have problems against spells that remove enchantments.

Some popular non-warrior tanking builds include:
 * Invincible Monk
 * Invincimentalist

Using the expanded definition of "tank", it is also possible for pets and minions to tank for a team. This feature is used to great effect in the popular Barrage/Pet builds (most commonly found in the Tomb ruins) that lack any damage-absorbing player characters.

Verb: to tank
Standing still and taking a beating from enemies instead of running away or kiting. Tanking is often used in PvE to make the healer's life easier (only one person to concentrate on). Tanking is especially effective in combination with Protection spells and stances.

It is important to be conscious of certain expectations while tanking:
 * Tank-on-Tank: This means that when assaulting an enemy group, the tanks should attract the aggro of the enemy melee fighters and keep it focused on themselves. Warriors who rush past the enemy warriors and head for the enemy spell casters make bad tanks because they allow the enemy warriors to get to their spell casters.
 * No running back: While tanking, warriors should not, when the going gets rough, run back with their tails between their legs. Instead, warriors should trust their monks and if concerned, they should run sideways and/or dodge. Pulling enemies into the heart of your spell casters is a sure fire way to kill a few of them as well as get your monks in a panic which means they will not focus on healing you.
 * Keep tanks alive at all costs: A tank that has suffered multiple deaths and is running aroud with, say, 35% DP is of little use to the party in terms of tanking. The reduction to health greatly limits their ability to take damage. As a monk, if you have to choose between healing the tank and healing an elementalist, keep the tank alive. The elementalist can operate with 35% DP from the back if the tank is doing his job, the reverse is not true. A warrior who does not tank and instead rushes off to kill enemy spell casters forfeits that privilege.
 * Prevention is better than treatment: With the exception of facing enemy mesmers who Shatter Enchantments, a group is best served by using Protection Prayers on their tanks (along with healing) than by just trying to spam healing on them. Protection allows the monks to control the amount of damage inflicted on tanks and protects from the unexpected hit that suddenly kills a tank.