What is Normalization in SQL?

Normalization is used to organize the data in such a manner that data redundancy will never occur in the database and avoid insert, update and delete anomalies.

There are some forms of Normalization:

First Normal Form (1NF): It removes all duplicate columns from the table. It creates a table for related data and identifies unique column values.
First Normal Form (2NF): Follows 1NF and creates and places data subsets in an individual table and defines the relationship between tables using the primary key.
Third Normal Form (3NF): Follows 2NF and removes those columns which are not related through the primary key.
Fourth Normal Form (4NF): Follows 3NF and does not define multi-valued dependencies. 4NF is also known as BCNF.