Necromancy (pronounced /ˈnɛkrɵmænsi/; Greek νεκρομαντία nekromantía) is a form of magic in which the practitioner seeks to summon "operative spirits" or "spirits of divination", for multiple reasons, from spiritual protection to wisdom. The word necromancy derives from the Greek νεκρός (nekrós), "dead", and μαντεία (manteía), "prophecy".
In Diablo a necromancer, is a "summon mage" Where do they get that idea if Necromancer redirects you to that on Wikipedia? That states that a necromancer is someone who talks to the dead, not summons them.