What Does XLR Connector Mean?
An XLR connector is a type of electrical connector used mostly in professional audio and video electronics cabling applications such as for stage microphones and other analog sound equipment, as opposed to home audio/video equipment using RCA connectors. It is characterized by a large cylindrical connector body, commonly with three prongs or pins, but other variants have anywhere from two to six pins.
Techopedia Explains XLR Connector
The XLR connector was an incremental variant that started from the Type O connector made by Cannon (ITT Cannon), which featured an oval-shaped body and receptacle with three prongs and a latch locking mechanism. Its actual predecessor was the X series without a locking mechanism, and by 1950 one was added and it became the XL series. By 1955, the female connector was modified to have synthetic rubber insulation surrounding the female contacts and this was now the XLR connector.