A classic of the genre. The adventures of a young wizard -- a wizardry school -- at a time when neither trope was exactly commonplace.
Young Duny learns bits and pieces of magic, starting with the time he accidentally learns a spell to make a goat come, and using it unwisely, ending up with a herd of goats which his aunt, the witch he learned the spell from, has to dispel. She teaches him more, he casts a fog spell that saves the village from raiders, and through that, the great mage Ogion comes and takes him as a prentice. He learns his true name -- Ged -- which he hides as they all do with a usename, his being Sparrowhawk.
Ogion is wise and cautious, and Ged, too eager to learn and urged by a girl he met, opens his books where he ought not to. Ogion sends him to the wizardry school at Roke, where he learns much -- and in a clash with a rival, casts a spell to summon a dead spirit. Something else comes with it. He nearly dies, the Archmage does, and the thing is loose in the world.
His further studies and his subsequent acts are all gravely affected by that. In a tale that involves dragons, meeting an old friend on the way at an odd hour, fleeing back to Ogion and gaining aid, a woman who knew him once and tells him he can overcome the thing he summoned, a little boy who dies, an old man and an old woman trapped on a tiny island, and much more, Ged must ultimately deal with it.