which classes are wanted in raiding? let me explain. Which classes are most likey to get in a raid period and why. Do not say because they need one to fill their slot i mean like wha classes are actually wanted for raids weather it be dps or buffig o w.e

and please tell me why,

Name them all if you can.

i only know Warrior - DPS/tanking, Pally- same, Druid- healer, mage dps, lock dps, what about shammys and huntards? and are warriors and pallys stricly wanted for tanking only or do people want them as dps as well?
alright and thanks yea i know they requie w.e class they dont have i been doing some research trying to find wat to role for raids ad keep seeing that everywhere i looked.