Connecting to the internet

To connect a computer or a device to the internet, you need:

Connectting to the internet with a router

Fibre optics

Fibre-optic cable

Fibre optic cabling is made from glass that becomes very flexible when it is thin. Light is passed through the cable using a transmitter. Light travels quickly through the light-reflecting internal wall of the cable.

The transmitter in the router sends light pulses representing binary code. When the data is received, it is decoded back to its binary form and the computer displays the message.


  • the individual cables are thinner, so larger quantities of cable can be joined together compared to copper
  • there is less interference than copper
  • there is less chance for degeneration


  • the UK telephone network still has areas that use copper cable
  • replacing copper with fibre optic cabling is expensive

Copper cable

Two electrical cables with copper wires twisted together

Copper cable uses electrical signals to pass data between networks. There are three types of copper cable: coaxial, unshielded twisted pair and shielded twisted pair.

  • Coaxial degenerates over long distances.
  • Unshielded twisted pair is made by twisting the copper cables around each other and this reduces degeneration.
  • Shielded twisted pair uses copper shielding around the twisted wires to make them less susceptible to interference.


  • a cabled telephone can be powered directly from the copper cable, so the phone will still work if there is a loss of power
  • copper can be cheaper to set up than fibre optic cabling


  • degenerates over long distances