Heat, energy and thermodynamics are fundamental concepts in physics that deal with the transfer of energy and the behavior of matter. Heat is the transfer of thermal energy between objects due to a temperature difference. It flows from hotter to cooler regions until thermal equilibrium is reached. Thermodynamics, on the other hand, studies the relationships between heat, work, and energy in systems. It encompasses laws such as the first and second laws of thermodynamics, which describe energy conservation and the direction of heat flow, respectively. Thermodynamics helps us understand processes like heat engines, refrigerators, and the behavior of gases and fluids. List of products available in this category are further sub-categorized below.