When a visitor to a web site types the name of a web site directly into the address bar of their browser, they arrive at site they have requested. This is called Direct Traffic. Web sites of well known companies with strong brands usually receive more direct traffic than other web sites.

You can use web analytics packages to measure how much direct traffic comes to a site versus referred traffic or organic search traffic.

Data are considerd to be portable if they can be moved from one system to another. In order to do this standards have to be defined for particular types of data.

At present the data portability debate is raging over who owns your personal data. It is particularly focussed on social networking web sites which use personal data that we enter and share with others.

It is often difficult to extract information that you have added on one of these sites and use it on another site and the site creators are accused of deliberately trying to lock people in to their service.

The address of a web site is known as a domain name. Any one can register a domain name if it is available. When you register a domain name, you do not own it, you are paying for the right to use it for a specific period.

Most people register a domain for one or two years at a time, though they can be registered for up to 10 years at a time. When your domain registration period ends, you will be given the option to renew the right to use the domain name.

The number of years that you renew the domain for is know as the domain renewal period.

A data centre is a secure building used by hosting companies to store their servers. They are usually specially designed secure buildings with sophisticated cooling and fire prevention systems, very fast connections to the internet and their own back up power supplies.

They store many thousands of servers in racks and hosting companies often build their own private rooms with in data centres. Each data cantre can host the computers of many thousands of different companies.