Annealing is heating the necks to around 600F. There is alot of contraversy on what temp to anneal too. Some say recrystalization won't happen until over 630F and some say below. Some say your just stress relieving.

I use heat sensitive paint like finger nail polish to know when I should throw in water. It softens the brass back up. Shooting several times works the brass and makes it brittle and then accuracy can go, and grip on your bullet is inconsistent.