In particular, a variable declared in the main program or in a procedure has the body of the program/pocedure as its scope.
A variable is local (has local scope) if its scope is that of a scoping unit.
A variable whose scope is the entire program has global scope.
Some variables can be seen by multiple program units - by extension we will also talk about global scope. Global storage (global scope variables) can be implemented using modules or common blocks. This is discussed later in this chapter.