What is data normalizaton?

Data Normalization - is the process of evaluating and correcting table structures to minimize data redundancies and reduce data anomalies (insert, update and delete).

It works through a series of stages called normal forms, typically 1,2 and 3 and uses the technique of identifying functional dependency to check compliance at each stage.

Basically it attempts to store data only once and in the correct place, so that when any changes are made to the database there is no chance that there is another copy of this information stored somewhere else and hence could lead to the above mentioned (insert, update and delete) anomalies.