Third Normal Form (3NF)
The same criterion applies as previously, namely that the table must be in 2NF before moving on to the Third Normal Form. Another requirement is that there be no transitive reliance on non-prime properties. That is, non-prime characteristics (those that do not constitute a candidate key) should not be reliant on other non-prime attributes in the same table. A transitive dependence is a functional dependency in which X → Z (X determines Z) indirectly, through X → Y and Y → Z (where Y → X is not the case).
Let us look at the following table and understand why it is not in 3NF:
