An ability is an effect (power, skill, or spell). Some examples of abilities are professions, or a hunter's , a warrior's , and a rogue's 50% healing reduction debuff due to 5 stacked charges of . Many effects generated by talents are abilities.
Your character's abilities can be found in their spellbook.
Depending on their availability and the method of obtaining them, abilities can be divided into several types: General, Racial, Class, Spec, Talent, Glyph 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 professions abilities) may also have other requirements, such as a certain number of skill points in the corresponding profession.
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, such as the riding abilities, or ; others come via professions, such as , or the profession passive abilities themselves; and many are gained as guild perks due to being in a guild of sufficient level. The only ability known by all characters at the time of creation is Auto attack.
Each race comes with its own selection of racials, including some passive and some active abilities - see racial for a full list. Race also determines which languages your character can speak, reflected in the Languages passive.
Class abilities are spells/abilities that are available to all characters of a given class, regardless of their spec. 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.
Spec abilities are spell/abilities that are only available to characters of a certain specialization. Some are shared between two or more specs, while others are unique to a single spec. Like class abilities, spec abilities are gained automatically when the character reaches the appropriate level. Since spec abilities are only available to characters of the appropriate specialization, choosing or switching your specialization will immediately grant you all spec abilities available at your level.
Talent abilities are spell/abilities that are accessible by all characters of that class, regardless of their spec. There are 6 tiers of talents for each class, with 3 potential talents on each tier. Tiers become accessible once the character reaches the appropriate level. Once a tier is unlocked, players are able to choose one of the three talents on that tier.
Glyph abilities are available to all characters of the appropriate class, by choosing the corresponding glyph. Most glyphs modify existing abilities (acting similarly to passive abilities), but some grant new, active abilities. Major glyphs tend to grant powerful abilities, while minor glyphs grant fun, entertaining ones.
Pets and warlock minions 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.
An ability rotation is a defined sequence of abilities that can be used to achieve a certain role in a group or raid. In other words, it can refer to the order in which a certain class will cast its spells or use its abilities in a PvE setting. Rarely if ever is there a defined rotation for a PvP situation.
Examples of abilities: