Databases

A database is structured collection of data. Thus, card indices, printed catalogues of archaeological artefacts and telephone directories are all examples of databases. Databases may be stored on a computer and examined using a program. These programs are often called `databases', but more strictly are database management systems (DMS). Just as a card index or catalogue has to be constructed carefully in order to be useful, so must a database on a computer. Similarly, just as there are many ways that a printed catalogue can be organised, there are many ways, or models, by which a computerised database may be organised. One of the most common and powerful models is the `relational' model (discussed below), and programs which use this model are known as relational database management systems (RDMS).

Database applications

Relational database management systems (RDMS) will typically provide a series of tools for creating tables, conducting searches, producing printed reports, With a complicated database, however, it is usual for a database application to be written. A database application is a usually a program within a program, it is a program that runs inside the RDMS. Most, if not all RDMSs, provide an `application development language.' This will allow a computer programmer to create an application to perform specific tasks for a particular database, most commonly to provide a simpler and more efficient method of inputting data to the database, and for checking for errors. Often this will use a series of forms with menus and buttons.