How many magic classes are there at Hogwarts?

There are four main magic classes at Hogwarts:

* Transfiguration: Turning one thing into another.

* Charms: Creating spells for a variety of effects.

* Potions: Brewing magical concoctions.

* Defence Against the Dark Arts: Learning to combat dark magic and creatures.

There are, of course, many other subjects taught at Hogwarts, but these are the four core magic classes.