RJ45

RJ45 is a registered jack standard for a modular connector using 8 conductors, which specifies the physical male and female connectors as well as the pin assignments of the wires. The "RJ45" physical connector is standardized as the IEC 60603-7 8P8C modular connector with different "categories" of performance, commonly known as RJ45.

The 8P8C modular connector - commonly referred to as an RJ45 in the context of Ethernet and Category 5 cables - is a modular connector commonly used to terminate twisted pair and multiconductor flat cable. These connectors are commonly used for Ethernet over twisted pair and other applications involving unshielded twisted pair, shielded twisted pair, and multiconductor flat cable.

Electronics catalogs commonly advertise 8P8C modular connectors as "RJ45", but of course an installer can wire the jack to any pin-out or use it as part of a generic structured cabling system using RJ45 patch panels for both phone and data. Virtually all electronic equipment which uses an 8P8C connector will document it as an "RJ45" connector.