Extension cords are a length of flexible electrical power cable (flex) with a plug on one end and one or more sockets on the other end (usually of the same type as the plug). The term usually refers to mains (household AC) extensions but is also used to refer to extensions for other types of cabling. If the plug and receptacle are of different types, the term "adapter cord" may be used. Extension cables are also used, but that has a distinct meaning from extension cords for many people.