1. Introduction

A database is a collection of data or information which is held together in an organised or logical way.

Databases can either be paper based or computerised, although hardly anyone these days uses a paper-based database.

Computerised databases

You will come across computerised databases in every aspect of your life. Here are some examples with which you will be familiar:

• Search engines e.g. Google, Bing
• School electronic registers
• Library database
• Shop stock control system
• DVLA - stores details of all driver licences and car registrations

Paper based databases

(it is unlikely that you will be asked about these in the exam) The point we are trying to make that a 'database' does not always involve a computer.

Paper based databases can be as simple as a notebook which contains addresses sorted by surname.

Other paper based databases can be much larger, for example, the Yellow Pages directory. The directory is organised by business type e.g.

• architects
• builders
• florists
• plumbers

Under each category are listed all of the local builders, sorted again alphabetically e.g.

• Bob the Builder
• Daffy Duck's driveways
• Mickey Mouse extensions
• Road Runner and son.