Can you explain what the second normal form in database normalization is?

Second Normal Form (2NF) is a stage of database normalization that requires the table to be in First Normal Form (1NF) and that all non-key attributes are fully dependent on the entire composite key, not just part of it.

In simpler terms, if a table has a composite primary key consisting of multiple columns, then no column that is not part of the key should depend only on a part of that key.

For example, if there is a table with a key (StudentID, CourseID) and a column StudentName, then StudentName depends only on StudentID, not on the entire key, which means the table is not in 2NF. To bring it to 2NF, StudentName should be moved to a separate table with the key StudentID.