The scope of a variable is the area where it can be “seen”. The use scope and set scope can be different, however.

The scope of a local variable is its routine. A local variable is created on entry to the routine and destroyed on exit from the routine. If a local variable is passed as an argument, then its value can be used in its own routine and in the called routine, so its use scope is its own routine and the routine that receives it. Because the value of an argument cannot be changed, its set scope is always its routine.