What is the difference of non void and void function?

If a method call is void, that means it will not return a data value to a program that calls it. Otherwise, the method is expected to return a data value of some sort.

For example, if I have a method called print() that is void, and the body of the method has a command to print a Word to the screen, the method will run that command and end.

However, if I have a method called add(int x, int y) that takes two numbers and adds them together, the program calling this method wants an answer back. So this method is not void.