What started out as a research project in the United States to create a network of computers with the ability to survive nuclear strikes that took out parts of it has now become a truly global medium linking people in a manner nobody foresaw.

When you connect to the Internet, your computer becomes a node on it. This is an important thing to remember: connecting to the Internet is not the same as making a telephone call, or watching broadcast television. Your computer will send as well as receive data, and thus is visible to other Internet users.

This means you need to pay attention to security for your computer, because there are unfortunately rogues – spammers, scammers and crackers – who are quick to abuse unprotected Internet-connected computers. Make sure your computer software is up-to-date and consider investing in a firewall.