AKA Registered Jack 45 or 8P8C


A telecommunications interface you’re likely to use when setting up a data network. The RJ45 is similar to the RJ11, except its connectors typically feature eight pins, and it serves as the interface for data—or Ethernet—networks instead of telephone networks. The clear plastic jacks of the RJ45 usually have a Cat 5 cable running between it, creating a connection between a network device (like a router) and a network card.