Database normalization is a method to organize tables in a relational database to eliminate redundancy and preserve integrity.

There are different stages of normalization with each stage building upon the prior stage.

First normal form (1NF) requires that each column contain atomic data and that no groups are repeated.

Second normal form (2NF) requires that non-key attributes be based on the entire key.

Third normal form (3NF) requires that all non-key attributes be based on the primary key.