What is the relationship between temperature difference and heat transfer?

Heat transfer is fundamentally driven by the temperature difference between two systems or objects. When there is a greater temperature difference, the rate of heat transfer increases because heat naturally flows from a hotter object to a cooler one until thermal equilibrium is reached. This principle is grounded in the second law of thermodynamics, which states that heat will always transfer in the direction that reduces temperature gradient. Therefore, the larger the difference in temperature, the greater the amount of thermal energy transferred. This relationship forms the basis for many applications in engineering and thermodynamics, including heat exchangers, HVAC systems, and various industrial processes where efficient heat transfer is essential.