Air conditioning units are devices designed to cool and dehumidify indoor spaces, making them comfortable during hot weather. They work by removing heat from the air inside a room and transferring it outside, using a refrigerant that absorbs and releases heat. Common types include window units, split systems, and central air conditioning, each suited for different needs and spaces. These units not only provide relief from heat but also improve air quality by filtering out dust and allergens. Regular maintenance, such as cleaning or replacing filters, is essential to keep them running efficiently and prolong their lifespan.