what the hell is the point of RJ-45??
Well, as RJ45 is a connector, it's main advantage is that it can be used for almost any device that requires 8 contacts. Hence you now see it used for various different network types as well as for serial ports.
In terms of the cabling attached to an RJ45, then the same applies, it's multipurpose. It gained popularity with companies during the late 1980s as a way of providing a single cabling infrastructure for different services, which was in the main cheaper than individual systems (coax, IBM T1, telecom etc). The common physical presentation also allowed 'flood wiring' of the workplace that allows for moves and changes far more easily than traditional types.
For home network users with more than two devices then yes, there is a downside - you need to buy a hub to connect them together (but the cost is pretty low).
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