What is built-in function? Explain its type i.e. Rowset, Aggregate and scalar. | Data Mining Interview Questions

A built in function of sql is used for performing calculations. These are standard functions provided by sql.
Aggregate functions: these functions perform calculation on a column and return a single value. Example: AVG(), SUM(), MIN(), MAX()
Scalar functions : these functions perform calculation on an input value and return a single value. Example: ROUND(), MID(), LCASE(), UCASE()