This post marks the first of what we intend to be a series of short items that hopefully debunk some of the most commonly used terms in application design and development.

Our first post is about Relational Databases (RDBMS) which refers to a type of data store. Most applications will need to store data that they collect such as user profile information. There are different data storage options available; Excel, Microsoft Access and FileMaker are examples of data stores that many people are familiar with. For web applications we need something that can store very large amounts of often complex data that can be accessed by many users at any one time. Today most people choose to use a Relational Database from one of the major vendors such as Oracle, Microsoft, IBM or Sun (MySql). The term relational refers to how data is stored. For example, customers in an ecommerce system may be grouped together in a table called ‘Customers’. Their orders may then be grouped into another table called ‘Orders’. To know which order belongs to which customer the two tables will be joined by a relationship.

Alternatives to Relational Databases are Document-orientated Databases, for example Lotus Notes, or Object Databases that utilise XML.