Wikipedia
A modular connector is a type of electrical connector for cords and cables of electronic devices and appliances, such in computer networking, telecommunication equipment, and audio headsets.
Modular connectors were originally developed for use on specific Bell System telephone sets in the 1960s, and similar types found use for simple interconnection of customer-provided telephone subscriber premises equipment to the telephone network. The Federal Communication Commission (FCC) mandated in 1976 an interface registration system, in which …
Modular connector - Wikipedia, the free encyclopedia