What is database normalization? Explain First, Second, and Third Normal Forms with examples.

Database Normalization is the process of organizing a relational database to reduce data redundancy and improve data integrity. It involves dividing large tables into smaller, related tables.

First Normal Form (1NF):

• Each column must contain atomic (indivisible) values
• Each column must contain values of a single type
• Each row must be unique
• Example: A column "Phone Numbers" storing "9841234567, 9851234567" violates 1NF. It should be split into separate rows.

Second Normal Form (2NF):

• Must be in 1NF
• All non-key attributes must depend on the entire primary key (no partial dependency)
• Example: In a table with composite key (StudentID, CourseID), if "StudentName" depends only on StudentID, it violates 2NF.

Third Normal Form (3NF):

• Must be in 2NF
• No transitive dependency (non-key attributes must not depend on other non-key attributes)
• Example: If a table has (EmpID, DeptID, DeptName), DeptName depends on DeptID not EmpID — this violates 3NF.