Although there are numerous scientific descriptions of what a RJ45 is in short it is the little bit of plastic that attaches to the end of a telecommunications cord and connects the cable to your telephone. It can be used to connect a wide variety of telecommunications cables with a wide variety of applications.

There are a number of different versions of the registered jack the RJ45 being one of them. The RJ in the acronym refers to registered jack and the variety of registered jacks is enormous to meet the vast range of connections that are made in telecommunications networks they are available to fit the size and shape of all types of port. The RJ45 connectors are generally used for a standard Ethernet connection. The Ethernet is the connection of a network of computers that are connected so that they can communicate with each other.

The RJ45 in this context refers to the connection on the end of a cable and there are a number of different cables that can be connected using a RJ45. One of these cables is the Cat 4 connection. This is a connection that connects four wire connections. The Cat 6 cable is similar with the Cat 6 connector enabling the connection of the 6 internal wires.

The Cat 4 and Cat 6 RJ45 cables allow different numbers of internal cables to be connected to an application. The cat 6 has six wires that are capable of performing data transfer but in this version typically only four are used. The reason that the manufacturers have included an extra two cables despite them being surplus to current requirements is that they are attempting to pre-empt the development of technology so that when faster data transfer can be achieved these cables will already have the capacity. This is similar to the theory of redundancy. This is the way in which cables make the most of the data that they transfer by compressing the data that they transfer to the smallest space possible. This means that the cables are extremely efficient.

What has now become the standard connector was first introduced in the 1970s to replace the connections that were originally used. The registered jack is not as bulky as the earlier versions and as a result replaced the earlier connection types. Aside from being less bulky the RJ45 also looked much cleaner and was as a result more aesthetically pleasing. There are a number of different RJ connectors and the different types of connector are denoted by different suffixes.

For example those with a C are flush mounted or surface mounted. The letter W refers to an RJ that is wall mounted whilst an S means that the RJ is a single jack. M refers to a jack that is multi line whilst X refers to a complex jack. The different jacks can be utilised in a wide range of different situations.