There are currently 3 types of magic cards:
Normal Magic Cards: These cards can be activated during your turn.
There are also a few of the such as De-Spell and Remove Trap that can
be activated during your opponents turn.
Equip Magic Cards: These types of magic cards can be attached to one of your monsters.
Field Magic Cards: These types of magic cards go above your opponents graveyard. They are used to power-up your monsters.