How Taunt Works

[Tpyo]

I was just wondering if anyone knows the specific mechanics on how taunt functions.

Back when I played classic, I never played a tank, therefor, I was always under the assumption that taunt was just a means for building aggro.

However, recently, I have been told that taunt simply resets a mobs aggro and sets the taunter to +1 above everyone else.

With this latter information in mind, wouldn't that mean a tank would only taunt when they lose aggro? I had always believed that taunt was spammed to keep aggro high...

I don't have a tank still... but really curious about the matter.