If you are referring to a language like C. The main function is a special function that is run first when a program executes. One usually tries to manage the other functions and the rest of the program from the main function. Wiki has some readings: http://en.wikipedia....on_(programming)
Perfection of means and confusion of ends seem to characterize our age. Albert Einstein :confused:
C++ is not restricted to pure OOP. You would do better to think of it as procedural programming that supports OOP, rather than just as OOP. int main() is simply a function.