brief introduction: RJ45 is a kind of information socket (i.e. communication outlet) connector in the wiring system. The connector consists of a plug (connector, crystal head) and a socket (module). RJ is short for Registered Jack, which means "Registered socket". In the FCC (Federal Communications Commission Standards and Regulations), RJ is the interface that describes the public telecommunications network, and RJ45 for computer networks is the common name for the standard 8-bit modular interfac