Do you use Ethernet? You might think that you don’t, but don’t be so sure. Ethernet is everywhere – if you use a networked computer, whether it’s at home or in your office, you’re using Ethernet. Ethernet is two things: a kind of cable for connecting computers together, and the method of communication that the computers use over the cables. Essentially, it is the glue that holds LANs (local area networks) together. The system works by giving each computer on the network a unique address, along with printers, scanners and other shared resources. They can then communicate with each other simply and easily. Ethernet originally had all sorts of limitations, but these have been gradually worked around as the years went by. Originally, for example, it was impossible for more than one computer to send data at a time – they had to take it in turns to ‘speak’, otherwise all the transmissions would get muddled up.

Every computer on the network received everything transmitted by the others, but simply ignored anything that wasn’t labelled with its address. Of course, this didn’t scale to very large networks, as no computer ever got a chance to transmit. The solutions to this problem are the reasons that Ethernet networks today are laid out the way they are. In order for many computers to use the network at once, lines are split into sectors, with a limited number of computers in each sector. These sectors are then connected together with switches. These switches reduce network congestion by only sending signals further out onto the network if they need to go that far – otherwise, they are simply dropped. There are many different kinds of Ethernet, each with its own mysterious name – 10BASE-T, 100BASE-TX, and so on. The only real difference between them, however, is the speed – 10BASE-T has a speed of 10 megabits (just over one megabyte) per second, while 1000BASE-T is more commonly known as gigabit Ethernet, because it can transmit a gigabit (125 megabytes) of data over the network every second.