This function is usually used inside Scripts, when you want to use a script as a function inside another command. The function returns exactly what it is passed, as in:
Value('This is what will be returned by the function')»«
The use of this script “as a function” would be something like
If(A = DemoValue())»Data Element A has the value “This is what will be returned by the function”.«
The contents of the Script in this case must be a fillpoint, and this fillpoint is invalid:
'This is what will be returned by the function'»
Hence the use of Value.