Equippable - These are spells that often require you to trace a pattern before you can learn them.
They offer new gameplay functions or mechanics.
Essential - These are considered "core" or "intrinsic" in that they'll always be active once you obtain them.
There are two primary classifications of spells in Hogwarts Legacy: Here's our Hogwarts Legacy best spells guide to help you acquire all the skills your character could use. Some act as mechanical functions intrinsic to the core gameplay, whereas others are primarily for combat.