What are types of efficiency?

There are many types of efficiency studied in different fields. In economics, there are three main types, productive efficiency where goods are produced at lowest possible cost, allocative efficiency where resources are distributed to produce what society wants most, and Pareto efficiency where no one can be made better off without making someone else worse off. In business and operations, there is operational efficiency measuring output per input, process efficiency measuring how streamlined workflows are, labor efficiency measuring output per worker hour, and energy efficiency measuring useful work per unit of energy. In engineering, there is thermal efficiency for engines, mechanical efficiency for machines, electrical efficiency for devices, and energy conversion efficiency. In finance there is market efficiency which is the Efficient Market Hypothesis stating prices reflect all information, with weak, semi-strong, and strong forms. In ecology there is ecological efficiency measuring energy transfer between trophic levels. In personal productivity there is time efficiency and personal efficiency. Each type uses the same core principle of maximizing useful output while minimizing wasted input, but applies it to different resources like money, energy, labor, or time.