#include <iostream> //The #include is a "preprocessor" directive that tells the
                    //compiler to put code from the header called iostream into
                    //our program before actually creating the executable.
                    //By including header files, you an gain access to many
                    //different functions.

using namespace std;            //This line tells the compiler to use a group
                                //of functions that are part of the standard
                                //library (std). By including this line at the
                                //top of a file, you allow the program to use
                                //functions such as cout. The semicolon is part
                                //of the syntax of C and C++. It tells the
                                //compiler that you're at the end of a command.
                                //You will see later that the semicolon is used
                                //to end most commands in C++.

int main()                      //This line tells the compiler that there is a
                                //function named main, and that the function
                                //returns an integer, hence int.
{                               //The "curly braces" ({ and }) signal the
                                //beginning and end of functions and other code
                                //blocks. Similar to BEGIN and END.
  cout<<"Hello world\n";        //The cout object is used to display text. It
                                //uses the << symbols, known as "insertion
                                //operators", to indicate what to output.
                                //cout<< results in a function call with the
                                //ensuing text as an argument to the function.
                                //The quotes tell the compiler that you want to
                                //output the literal string as-is. The '\n'
                                //sequence is actually treated as a single
                                //character that stands for a newline. It moves
                                //the cursor on your screen to the next line.
                                //The semicolon is added onto the end of all,
                                //such as function calls, in C++.
  cin.get();                    //This is another function call: it reads in
                                //input and expects the user to hit the return key.
                               //Upon reaching the end of main, the closing
                                //brace, our program will return the value of 0
                                //(and integer, hence why we told main to return
                                //an int) to the operating system. This return
                                //value is important as it can be used to tell
                                //the OS whether our program succeeded or not.
}