What is 3NF in database design?

The 3NF form is a "eliminate columns not dependent on the key" in the database design.

Explanation:

3NF form stands for third normal form says that it is necessary to remove all column that references to all related information that is not based on the primary key.

It is difficult to store data into one table to remove this problem we use the normalization, there are many forms in the normalization that are "1NF, 2NF, 3NF, and BCNF". The main purpose to use 3NF (normal form) in the database is to remove the data duplication.