An air conditioner is a device that cools and dehumidifies the air in a room or building. It works by removing heat from the indoor air and transferring it outside, making the indoor environment more comfortable, especially during hot weather. Most air conditioners have a thermostat that allows you to set your desired temperature. In addition to cooling, air conditioners can also help improve indoor air quality by filtering out dust, pollen, and other allergens. Many modern units are energy-efficient, which means they use less electricity while still providing effective cooling. This can help save money on energy bills while keeping your space comfortable.