Usability
Part of speech: noun
Definition: The state or condition of being usable. The degree to which an object, device, software application, etc. is easy to use with no specific training.
Utility
Part of speech: noun
Definition: The state or condition of being useful; usefulness.Something that is useful.The ability of a commodity to satisfy needs or wants; the satisfaction experienced by the consumer of that commodity.A service provider, such as an electric company or water company or its securities.A software program specifically designed to help manage and tune the computer hardware, operating system or application software, and perform a single task or a small range of tasks; as opposed to application software which tend to be software suites.