What is the Difference Between Capability and Ability?
When to Use Ability
Ability is a noun. It refers to possession of the means or skill to do something.
Someone with superior athletic abilities is very good at sports or other physical games. A writer of great ability is considered to be an excellent writer. In both cases, ability is used to refer to the qualitative nature of the person.
When to Use Capability
Capability is also a noun, and it also refers to the ability to do something. The difference between capability and ability is usually one of pragmatics.
Capability usually refers to either/or propositions in a potential scenario: a corrupt regime may have nuclear capabilities. It can either launch nuclear missiles, or it cannot. A fighter jet may also have stealth capability. It either has this capability, or it does not. In this sense, capability is a quantitative marker.
Is it capability or ability? Both words refer to having the power to do something.
In general, abilities can vary along a continuum; one person may be better at free throws than other person, for example. Capability is usually an either/or proposition; a country can either launch nukes or it can’t.