Desired characteristics of a database include it being efficient in terms of storage and easy to maintain.
The first point, of storage, means redundant data should be avoided and the second point, of maintenance, means that a good design will logically separate data into tables.
Normalisation is a design method that can be used to achieve this.
What is normalisation?
“a technique for designing relational database tables to minimize duplication of information and, in so doing, to safeguard the database against certain types of logical or structural problems” (wikipedia.com)
Normalisation provides rules that help:
- organise the data efficiently.
- eliminate redundant data.
- ensure that only related data are stored in a table.
This mini-website will describe this process and the terms you need to understand.