"Tanking" in this game and many MMOs is using a player with strong defense (high health and resist, shields, healing) to absorb damage for a team. This protects the more offensive players who can do more damage, but have low health and resist.
Usually the player who enters a fight first, or attacks first, draws a lot of the enemy attention. The most common 'tank' school in W101 is Ice, but others can do it too with the right gear.
A "tank" is a player with high health and resist that goes first to draw fire away from the rest of the players. In team battles you typically have tank, support, healer, and hitter.Tank draws fire, support blades and traps, healer heals, hitter hits. Pretty basic team dynamic, you can be more than one in cases. My Balance for example plays Tank, Support and Healer all at the same time leaving the rest of my party to be Hitters.
Tanking is having one person absorb all the damage so everyone else can focus on attacking.
Let's say you have 3 storm and an ice. The 3 storms are really weak, health wise, while the ice doesn't hit as hard. Instead of having everyone just try to attack, the ice could use taunts and tower shields to make sure that the enemies only attack him/her and barely do any damage, allowing the storms to hit really hard without having to worry about keeping themselves healed. In that situation, the ice would be tanking.
It's not really the best strategy in W101, simply because taunts don't work that well and even ice can do a lot of damage. The strategy is from other MMOs. In World of Warcraft, for instance, all dungeon groups have 5 people: one tank, one healer to keep the tank alive, and 3 people doing damage.
I believe it is basically the wizards who shield and protect the other wizards in a battle. So primarily i believe being "A Tank" is a wizard who is always protecting the other more vulnerable team members so "tanking" would be the act of this. Just an assumption, I may be wrong but I hope it makes sense anyways.
Tanking is basically just having high resist and being able to take a bunch of damage without getting killed.
Best tanking gear: Jade gear.
Basically, the person with really high resist goes in first and gets the battle started, after the first turn has started all others join.
This makes all the enemies target them instead, unless it's an attack all spell or someone else attacks and gains aggro towards the enemy.
The person who goes in first and has high resist is called a Tank, while the other 2-3 people in the fight are called Hammers, What the Hammers do is blade up/put on traps etc to power up a big hit. Usually a one-hit kill attack.
In this game genre, there are four commonly used terms to describe a player's role during a fight, or duel as it is known in Wizard101. They are, Tank, Damage, Healer, and Support. I will give you a brief description of each and hope this helps you in your gameplay.
"Tank" is the player who attempts to keep the focus of the enemy on him/her during the entire time of the duel, so that others can perform their duties with greater ease.
The "Damage" and "Healer" responsibilities are pretty easy to figure out.
"Support" is the player who attempts to fill in gaps in group damage/healing/shielding.
I hope this helps you, and good luck in the Spiral.