How does data travel over a cable?

Transferring data through a cable uses the same principle as conducting electricity along a length of metal wire. At its most simplistic, data sent over a cable is converted into binary code – a collection of 1s and 0s. The device transmitting the data will send current along the cable at two different voltages (for instance, 0V and 5V), with one voltage representing 1s and the other 0s. The device receiving the data will interpret that current as binary code, and then convert that back into the original format the data was before it was sent.  The volume and speed of processing data over a specific timeframe is covered by the Ethernet Standards.

Fibre optic cables work in much the same way – but instead of transmitting electrons down a cable they send pulses of light (imagine turning a torch on and off – when the light is on, you are transmitting a 1, and when it’s off you are transmitting a 0). Because light travels further and faster than electrons, fibre optic cables are capable of transmitting much more data than copper cables, because light travels faster than electricity. 

In today’s digitised world, almost every industry relies on data flowing through cables. In particular, data centres, telecommunications, industrial automation, financial services, healthcare and the emergency services all rely on transmitting data over cables – sometimes over significant distances. This is often because data travels faster over cables than it does over wireless connections and offers greater reliability – so in the emergency services where the speed at which data is delivered can literally save lives, a high-quality cable network is preferred for transferring data than a wireless connection.