The IIf function denotes immediate decision function. It provides a simple decision-making process based on three arguments, as follows:

IIf(x, y, z)

x represents a logical expression while y and z represent a numeric or a string expression.

For example, the IIF(x>y, expression 1, expression 2) function evaluates the values of x and y, if x>y. then expression 1 is true, otherwise, the expression 2 is true.

To learn more about the function and its application, follow the link below:

http://www.vbtutor.net/lesson7.html