Normalization is the process of designing a data model to efficiently store data in a database. The end result is that redundant data is eliminated, and only data related to the attribute is stored within the table. So we can say that normalization is the chain of steps and this chain of steps take a relation from one Normal Form State to another Normal Form State until we get to the desired Normal Form State.
There are six different normalization methods as follows:
(1) 1st Normal Form: Each field in a table contains different information. For example, in an Customer list, each table would contain only one Customer ID field.
(2) 2nd normal Form: Each field in a table that is not a determiner of the contents of another field must itself be a function of the other fields in the table.
(3) 3rd Normal Form: We say that a relation is in 3NF if it is in 2NF and has no transitive dependencies.
(4) Boyce-Codd Normal Form: also known as BCNF A relation is said to be in BCNF if and only if every determinant in the relation is a candidate key.
(5) 4th Normal Form: A relation is said to be in 4NF if it is in BCNF and contains no multi valued attributes.
(6) 5th Normal Form: A relation is said to be in 5NF if and only if every join dependency in relation is implied by the candidate keys of relation.
(7) Domain key normal Form: We say that a relation is in Domain Key Normal Form (DKNF) if it is free of all modification anomalies. Insertion, Deletion, and update anomalies come under modification anomalies.