Heating and cooling units are systems designed to regulate indoor temperatures for comfort. They can be categorized into two main types: heating units, which warm up spaces during cold weather, and cooling units, which lower temperatures in hot conditions. Common examples include furnaces, air conditioners, and heat pumps. These units work by transferring heat energy. Heating units often use fuel or electricity to generate warmth, while cooling units typically remove heat from the air. Proper maintenance of these systems is essential for efficiency and longevity, ensuring they operate effectively throughout the year.