Hydrofluorocarbons, or HFCs, are a group of synthetic compounds primarily used as refrigerants in air conditioning and refrigeration systems. They were developed as alternatives to ozone-depleting substances like CFCs and HCFCs, helping to protect the Earth's ozone layer. While HFCs do not harm the ozone layer, they are potent greenhouse gases that contribute to global warming. Efforts are underway to phase out HFCs under international agreements like the Montreal Protocol, promoting the use of more environmentally friendly alternatives.