Line 3: Every C++ program must have a function known as main(). It is referred to as the entry point for the application when you start execution of the program on your computer. The int portion is the return type of the method. The empty parentheses () after the name indicate that this a function and that it takes no arguments, in other words, there are no parameters for passing in values. You will learn more about variable types, return value and arguments in the future.