In a relational database management system (DBMS), a super key is a set of one or more attributes (columns) that can uniquely identify a row or a tuple in a table. All super keys cant be candidate keys, but the reverse is true. A candidate key is a minimal super key that cant be reduced to a simpler super key by removing an attribute. In a relation, the number of super keys is more than the number of candidate keys. The role of a super key is to identify the tuples of a specified table in the database. All those attributes in a table that can identify the other attributes of the table in a unique manner are all super keys. Super keys are used for functional dependency determination and normalization, while candidate keys are used for primary key selection and uniqueness constraint.