AND operator.
The AND operator is one of the logical or Boolean operators in VB Script (and in fact, many programming languages). Some of the other operators are OR, NOT and XOR. With the AND operator, when there is a chain of conditions, every condition in the chain must evaluate to true in order for the entire expression to be evaluated as true.
For example, consider the following
(2 < 3) AND (4 > 5)
This will evaluate to false since the first condition (2 < 3) is true but the second condition (4 > 5) is false. i.e
=> true AND false will produce false