Proficiency vs. Efficiency — What's the Difference?

The state or quality of being proficient; competence.

Efficiency is the (often measurable) ability to avoid wasting materials, energy, efforts, money, and time in doing something or in producing a desired result. In a more general sense, it is the ability to do things well, successfully, and without waste.

Ability, skill, competence.

The quality or property of being efficient.

The quality of having great facility and competence

The degree to which this quality is exercised

Skillfulness in the command of fundamentals deriving from practice and familiarity;

The ratio of the effective or useful output to the total input in any system.

The ratio of the energy delivered by a machine to the energy supplied for its operation.

An efficiency apartment.

The extent to which time is well used for the intended task.

(dated) The quality of producing an effect or effects.

The extent to which a resource is used for the intended purpose; the ratio of useful work to energy expended.

(US) A one-room apartment.

The ratio of the output to the input of any system

Skillfulness in avoiding wasted time and effort;