A window air conditioner consists of four main components: the compressor, which circulates refrigerant; the condenser, where the refrigerant releases heat; the evaporator, which absorbs heat from the room air; and the expansion valve, which regulates refrigerant flow. It also includes a fan to circulate air, an air filter to trap dust and debris, and a control panel for adjusting settings. The unit is encased in a durable housing, designed to fit securely in a window or wall opening.