Define the Third Normal Form:
The third normal form (3NF) is a normal form employed in database normalization. 3NF was initially defined by E.F. Codd in 1971. Codd's definition defines that a table is in 3NF if and just only if both of the following conditions hold: The relation R (table) is in second normal form (2NF)
Each non-prime attribute of R is non-transitively dependent ( that is directly dependent) on each key of R.