title: main () returns an integer?
body: <p>I am currently reading what functions are in c++. It says that they are "artifacts that enable you to divide the content of your application into functional units that can be invoked in a sequence of your choosing.A function, when invoked, typically returns a value to the calling function." </p>
  
  <p>It then goes on to say that main() is recognized by the compiler as the starting point of your c++ application and has to return an int (integer).</p>
  
  <p>I don't know what is meant by 'has to return an integer'. From my (<strong>extremely</strong> limited experience) int main () is the start of your application. But what is meant by 'has to return an int'?. This is also intertwined with me not understanding 'typically returns a value to the calling function'</p>