Introduction
Databases are devices that allow you store data in a way that is easy to search to find the exact bits of the information you want whenever you want them.
The first databases were mainly used by computer programs and the ways of searching them were very complicated and intricate and very much tied to a particular process so the data in them could not be easily be used for anything else without reprogramming. However they were quite efficient for the type of data processing required at that time - which was mainly handling large numbers (billions) of transactions of the same kind.
Then in 1970 E F Codd a mathmatician and researcher at IBM published his idea of a more 'universal' type of database i.e. a multi-purpose tool that can store any data which can then be used for any purpose.
E F Codd's suggestion was based on a branch of mathematics called relational theory and it is basically a way of giving databases a consistent and logical way of handling data no matter what the data is about or what it is going to be used for.
It took a while before these ideas were taken up commercially - but by the 1980s 'relational databases' as they were called were beginning to appear. The first one was Oracle®, followed by IBM's DB2® and since then many others. In fact since the 1980s nearly all databases in use are this type of database.
However it shouldn't be thought that the story of databases is only about relational databases. People have continued to develop databases for other uses, often specialist areas in maths and science, but also for some business applications.