What is the meaning of the second normal form?

The Second Normal Form (2NF) is based on the First Normal Form (1NF). A table is in 2NF if it is in 1NF and all non-prime attributes are fully functionally dependent on the primary key.

This means that each non-prime attribute must depend on the entire composition of the primary key if it is composite, and not just part of it. In other words, there should be no partial functional dependencies.

The goal of transitioning to 2NF is to eliminate data redundancy associated with partial dependencies and to prevent update, delete, and insert anomalies.