what is the difference between a macro and a variable
Using a macro instead of a variable will give you the same result as
using a variable over a macro. The only difference is the way it is they
are compiled. A variable is compiled using the compiler where everytime
you put your variable name, it will treat it as it would treat the
variable's value. Macros are used by the precompiler which will find your
macros in your code, and replace the macro with your macro's value.