The term for the energy transfer that occurs between trophic levels is known as nutritional energy transfer or energy flow. This process illustrates how energy is passed along the food chain from one trophic level to the next, starting with primary producers that convert sunlight into chemical energy. Typically, only about 10% of energy is transferred to the next level, with the rest lost as metabolic heat or used for growth and reproduction. This concept is crucial for understanding ecosystem efficiency and population dynamics.