2. Social networking

A social network site allows you to post messages, upload pictures and stories on to your own personal page. You can include favourite videos clips along with your 'likes'.

Friends, family and colleagues can then visit your page to see what is going on.

They can also post comments and messages on your page and you can do the same to their page.

As soon as you make a change to your page, that can be sent as 'news' to your friends' page.

Some of the sites also provide blogs, forums, automatic links to your favourite music artists, online games and other 'Apps'.

This constant exchange of personal information, gossip and news is what social networking is all about.

Twitter is a little different in that you can only post very short 140 character comments, but it is an amazingly effective way of keeping up with gossip and news from people with similar interests.

To join a social network, you have to provide some personal information. This is called your 'personal profile'.