The XLR connector is a rugged electrical connector design. XLR plugs and sockets are used mostly in professional audio and video electronics cabling applications. Home audio and video electronics normally use RCA connectors.

The most common is the 3-pin XLR3, used almost universally as a balanced audio connector for high quality microphones and connections between equipment. XLR4s with four pins are used for ClearCom, Tecpro intercom systems, 12 volt power, and the older AMX analog lighting control. The XLR5 is the standard connector for DMX digital lighting control

XLR cable has pins or sockets (male or female, you'll figure it out) used with two-conductor shielded cable for microphones or high-quality balanced equipment (such as DAT player). The cables are usually male to female, so they can be extended by connecting one to another. A locking mechanism requires you push down a tab to release them. Absolutely the best choice for long cable runs.