Answer:   You pass an argument by value by specifying the ByVal keyword for the corresponding parameter in the procedure definition. When you use this passing mechanism, Visual Basic copies the value of the underlying programming element into a local variable in the procedure.

Answer:   ByVal means that we are passing a copy of a variable to our method or function. The purpose of using ByVal keyword in VB.NET is to preserve the original variable and not allowing its value to be getting altered.