eficiena

EficiAn a is a concept that describes the ability to achieve a desired result with the least possible use of resources. In science and engineering, efficiency is defined as the ratio of useful output to total input, and it is typically expressed as a dimensionless fraction or a percentage. Mechanical efficiency refers to useful work divided by energy supplied to a machine; thermal efficiency is useful energy or work obtained divided by the energy provided as heat; electrical efficiency is the ratio of power delivered to the load to power drawn from the source.

Efficiency values range from 0 to 1 (0% to 100%), and real systems exhibit losses such as friction, heat dissipation, and other irreversibilities that keep efficiency below 1. In energy and manufacturing contexts, higher efficiency means reduced resource use and operating costs, while in other domains it can indicate better use of time, materials, or energy.

Applications span many fields. In vehicles, engine and drivetrain efficiency affects fuel consumption; in power generation, turbine and generator efficiency influence overall plant performance; in electronics, converter efficiency measures loss during voltage and current transformations; in buildings, energy efficiency measures reduce heating and cooling demands. Efficiency is also a key idea in productivity and process optimization.

Efficiency is closely related to, yet distinct from, effectiveness. Efficiency concerns how economically resources are used to achieve a result, whereas effectiveness concerns whether the desired result is achieved at all, regardless of resource use. The concept is central to sustainability, cost management, and performance improvement.

In Romanian usage, the term corresponds to eficiENța, often written without diacritics as eficiena. It appears across science, engineering, economics, and everyday language.