- A relation is said to be in third NF if and only if, it is in second NF and no non-key attribute is transitively dependent on primary key whereas, a relation is said to be in BCNF if and only if every determinant is a candidate key.
- Third normal form is weaker than BCNF whereas BCNF is stronger than third NF as it removes all the anomalies of the 3NF which occurs because of overlapping candidate key.
- Third NF has reference to first and Second NF whereas BCNF does not refer to First and Second NF.
- The relation not in BCNF could be in 3NF whereas The relation not in 3NF could never be in BCNF.
- 3NF could contain overlapping candidate key whereas BCNF could not contain overlapping candidate keys.