n The act of performing; carrying into execution or action; execution; achievement; accomplishment; representation by action; as, the performance of an undertaking of a duty.
n That which is performed or accomplished; a thing done or carried through; an achievement; a deed; an act; a feat; especially, an action of an elaborate or public character.
n (computer science) The amount of useful work accomplished by a computer system compared to the time and resources used. Better Performance means more work accomplished in shorter time and/or using less resources