Allocative efficiency is concerned with WHAT is produced.

Productive efficiency is concerned with HOW things are produced.

Distributive efficiency is concerned with WHO things are produced for.

If we have allocative, productive, and distributive efficiency -- we have ECONOMIC EFFICIENCY.

ECONOMIC EFFICIENCY is achieved when we produce the combination of outputs with the highest attainable total value, given our limited resources.

Economic efficiency, in broad terms, means that it is impossible for anyone to gain unless someone else loses.

We have Pareto Optimality when it is impossible to make anyone better off without making someone else worse off.