First Normal Form and second normal form
First Normal Form (1NF)
A relation is said to be in 1NF if it having no non-atomic values and each row can give a unique combination of values.
Second Normal Form (2NF)
A relation is said to be in 2NF f if it is already in 1NF and each attribute fully depends on the primary key of the relation. Speaking inversely, if a table has some attributes which is not dependant on the primary key of that table, and then it is not in 2NF.