What is a database?

A database is a collection of data which has been organised so that a computer program can quickly select desired items. This could be something as straightforward as a list of names in alphabetical order or an ascending list of numeric stock codes. The secret to the successful use of database technology is the way in which data or information is structured to enable efficient processing.

Manual filing systems have drawbacks that make them inefficient. Take as an example a simple card file index of customer information. This depends on consistent use to be effective. For example, if the card always has the surname in the top left-hand corner then they are easy to put in alphabetical order. However, if some cards have the postcode in this position instead, the task becomes more complicated.

Databases are designed to store and manage data in a controlled and structured manner.

Single-card file indexes can be simple, but it is more complex to cross-reference information held in two separate files. The relational database management system (RDBMS) makes use of common "keys" to tie related information together. For example, a customer ID number could be used to identify an individual customer in a large list of customers, or to link a customer with an order for specific goods.

Subjects covered in this guide


Information Systems
Online Databases
Data Driven Websites