What best defines the term 'energy'?

The term 'energy' is best defined as the capacity for producing effect. This definition encapsulates the fundamental nature of energy, which is the potential to perform work or produce change in a system. Energy exists in various forms, such as kinetic, potential, thermal, and chemical energy, and is a key concept in physics, engineering, and various other disciplines.

Understanding energy as the capacity for producing effect highlights its role as a driving force behind numerous processes and systems. For example, in mechanical systems, energy is what enables movements and interactions between components; in electrical systems, it powers devices and drives electrical currents.

The other definitions provided, while related to energy, do not fully capture its essence. For instance, measuring force, total work over time, or the amount of power generated are all aspects or consequences of energy but do not define what energy fundamentally is. Therefore, recognizing energy as the capacity to effect change allows for a broader understanding of its applications and implications in various scientific and practical contexts.