The standard output stream is a pointer to a complex FILE structure named stdout. This stream sends all characters to the console screen formatted by the printf() function. We can think of this stream as a never-ending flow of characters from our program to the screen. It may not look like that onscreen because of the control characters, which alter how characters appear. These include carriage return (CR), new line (NL), form feed (FF), horizontal tab (HT), and vertical tab (VT). Other control characters change how the screen appears when we delete or rub out characters. These include backspace (BS) and delete (DEL). Nevertheless, these characters appear in the stream flow to the console program; the console program either simply prints them or interprets and changes the position of where the next character will be shown on the screen.
One complication to the flow of characters in the stream is that they aretypically buffered....