Magic

Magic is the primary ability of unicorns. It is this power unicorns are capable of spells such as leviation to more advance spells such as to transform objects into other items or to manifest them from nothing. Magic tends to be used by unicorns in their daily lives, such as basic levitation spell used for moving or carrying items.

Each unicorn has various levels of magical power, usually at a minor amount suited for their special talent. Twilight Sparkle being the acception due to her special talent is magic itself and also Princess Celestia and Princess Luna for their status. while Discord is not a unicorn or a pony, he is capable of reality warping magic which he puts into use for his chaos.

Spells
Unicorns can learn various spells to put their magic into uses. Spells are how unicorns use their magic. Unicorns can learn how to do spells from teaching or books and they are performed through concentration than incantations.

Elements of Harmony
The Elements of Harmony are known as the most powerful of magic in all of Equestria. There are 6 of these elements, 5 are named and based on attributes and bestow it's magic on ponies with behavior closely assosiated with these elements, even if they are not unicorns. The sixth element is known as "Magic". Unlike the other elements which take the form of necklaces, this element takes the form of a tiara and Twilight is able to use it with her friends.