Every name in a C++ program must refer to a unique entity (an object, function, type or template). a name can be reused to refer to different entities provided that there is some context by which the different meanings of the name can be distinguished. The general context used to distinguish the meanings of names is scope.
C++ supports three forms of scope:
In C++, the scope of a variable ends with first encountered
closing braces }. Declare variables close to
the code where they are used and where they can be
initialized is particularly useful in large procedures with
many local variables. This improves code readability and
helps avoid type-mismatch errors.