You may have noticed two characters near the end of our printf() statements \n. These don't get displayed to the screen, they are the notation printf() uses to represent "newline". '\' is the c escape character when it is encountered within quotes the following character usually has a special meaning. Another example is \t which is used to represent a TAB.
Another special character that printf() looks out for is '%', this tells it to look at the next few characters and be ready to replace them with the value of a variable. %d is the character sequence that represents a variable of type int to be displayed using the decimal counting system (0 .. 9). For every %d in the format string you must tell printf() what variable you want it replaced with. Here's some more use of printf() in code: