Difference between Decode and IIF in oracle?

DECODE	IIF
Decode can be used in Select statement	IIF cannot be used in a Select statement.
EXAMPLE: DECODE(deptname,”SALES”,1,0) —-If deptname is SALES then return 1 else return zero	EXAMPLE:IIF( GRADE > 1, IIF( GRADE < 2, SAL1, IIF( GRADE < 3, SAL2, IIF( GRADE < 4, SAL3, BONUS))), 0 ) —-If the GRADE less than ONE then return zero else return SAL1 OR SAL2 OR SAL3 OR BONUS
Decode gives better readablity to users	IIF dosenot give good readablity

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Ur's Hari