In World of Warcraft the idea of mana managing seems far-fetched considering all you have to do is sit down and drink some water. But what if you sit down to drink, you only have 30% mana and the tank pulls or accidently pulls, and knocks
you out of drinking? You’re all going to die! Unless you know how to manage that last bit of mana to keep the tank and everyone else alive.

Read the guide on Mana Managing as a Holy Priest Here