Relational Database - Definition
A database is an electronic storage system for data in raw form which can be used to glean information about that data in a useful and helpful form. A database system, such as a program like Microsoft Access, allows you to gain information from the database as a whole or select parts of the database, because all of the separate parts of the database are connected together.
A relational database contains several different units of data storage, called tables. Each table will contain fields that store information. An example of a field label would be "last_name" or "postal_code". An example of a table name would be "customer_addresses". The relational database allows you to connect several tables together. For example, a store might have a customer information database. The owner could query the database for information such as: a list of all customers that live on Oak Drive who bought more than $50 worth of merchandise in the last year. The ability to do this depends on a sound database structure.
The ability to have many tables, all connected together in one database, allows you to avoid repetition of data. For example, one table would be called "customer_addresses", and it would contain fields such as "last_name", "first_name", "street_address", etc. Another table in the database might be called "customer_accounts". This table could use ...
A relational database is emphasized.