Depending on their availability and the method of obtaining them, abilities can be divided into several types: Command,Class, Support and Pet.
Most abilities have a level requirement, and are only available to learn once the character has reached the required level. Some (such as job skill abilities) may also have other requirements, such as a certain number of skill points in the corresponding job skill.
General abilities are abilities that any character can learn, regardless of class. There are many sources of general abilities: some can be learned from trainers,others come via job skills, such as Cooking Fire or the profession passive abilities themselves.
Class abilities are spells/abilities that are available to all characters of a given class. Some are known by characters at the time of creation, while most will automatically be taught to players when they reach the appropriate level. The ability to use weapons and armor is also determined by class.
Auto-Abilities are abilities that enhance a character. They are also called passive abilities, job traits or Support Abilities. They range from providing bonuses to improving equipment options, general stats, physical or magical resists, and so on. Some auto abilities are innate to a particular job or monster.
Pets have abilities of their own. Classes with pets will find their current pet's active and passive abilities listed in their spellbook, once they have learned to command their pets.