Static as a file global variable

As you may be aware, C++ is a programming language closely related to the C programming language. C++ was designed to have most of the same functionality that C had and then added more things to it. C was not object-oriented, and so, when it created the static keyword, it was used to indicate that source code in other files that are part of your project cannot access the variable, and that only code inside of your file can use it. This was designed to create class-like behavior in C. Since we have classes in C++ we don't typically use it, but I felt I should mention it for completeness.