We have learned several facts in this section:
- We hold information about objects such as Product, Employee, DVD, etc. These items of information (such as Product-Code, Product-Name) we actually call Attributes.
- One of the attributes is usually designed to uniquely identify an occurrence of the object. We call this attribute the Key. For example Employee-Number, DVD-Serial-Number, Product-Code.
- We can ask questions of our set of data.
However, holding data on cards or some similar medium is not efficient in today's technological world and nowadays we hold our sets of data in a product known as a Database package.
(In fact our DVD records, discussed above, also form a database and the medium is cards).
As far as electronic databases are concerned there are several architectures in existence. However in this unit our design and implementation of databases will use what is called the Relational Database Model.