There are several rj plugs similar construction and the same method of installation
All these connectors have a monolithic rj connector cover made of plastic and gold-plated contacts with knives digging into the wires. The installation of the connector consists in inserting wires into oblong, parallel holes and then crimping the contacts with a special tool - crimping tool. Knives in the contacts dig into the wires, ensuring the connection and immobilizing it.
RJ-45 plugs have 8 contacts. In most applications, a LAN cable called twisted pair is installed to the connector. It consists of 8 wires - 4 pairs. Each pair is twisted. In addition, all pairs are twisted along the axis of the cable. This reduces external interference and crosstalk between channels - pairs.
A typical cable installation is shown in the diagram: