Which statement correctly describes the purpose of the first three normal forms (1NF, 2NF, 3NF) in relational database normalization?

• A. We only have 4 normal forms; 1NF is the strongest.
• B. 1NF reduces repeating groups; 2NF removes partial dependencies; 3NF removes transitive dependencies.
• C. 1NF and 2NF are the same; 3NF is about primary keys.
• D. Normalization eliminates all constraints.

Answer: (B)

At the heart of normalization is organizing data so that each fact is stored once and only where it belongs, reducing redundancy and update anomalies. The first step makes sure every value in a column is atomic—that is, not a list or set of values—and that each row is uniquely identifiable. This eliminates repeating groups, so the table represents a single, consistent relation.

Building on that, the second form addresses how attributes relate to the key when the key is composed of multiple parts. If a non-key attribute depends only on part of that composite key, you’ve got a partial dependency. Removing those by splitting the data so that the attribute depends on the whole key aligns with the goal of ensuring each fact is stored with the appropriate key context.

The third form tightens this further by removing dependencies where a non-key attribute depends on another non-key attribute rather than directly on the key. These transitive dependencies can still lead to anomalies, so eliminating them keeps non-key attributes firmly tied to the primary key.

So the sequence described—eliminating repeating groups, removing partial dependencies on a composite key, and then removing transitive dependencies—correctly captures the purpose of the first three normal forms.