Character trade

Hi, i am back from a long break from wow, and i just saw a character trade "thing" option,is it like a shop only, say i sell/buy character for coins, or can i swap/trade characters with some other person, say i trade a lvl 75 priest for a lvl 75 warlock or something? is that possible

Is it possible to trade characters instead of buying them for coins?

I'd like to get an answer for this aswell.