In this video, we show an example of how you can use the printf function to print output to the terminal. We have our usual frame for main as well as a box for output. And the execution arrow is at the start of main. We begin by declaring and initializing a to 42. Then we reach a printf call. We're going to print the string Hello World. It'll just print this string directly, there are no formats specifies at all. So our output is Hello world. The next printf call with print the string a. Note that this prints the literal letter a since it is enclosed in quotation marks and is therefore a string literal. This has nothing with the variable a. So our output is a. And we return 0 and exit main. What would you do if you wanted to instead print the value of the variable a? The f in printf stands for formatted, and there are several format specifiers you can use to format your output. In this example, first we declare and initialize integers a to 42 and b to 7. Then we reach a printf call with a format specifier. In this case, %d. %d formats integers as decimal numbers. And you'll learn later about other format specifiers. %d means printf will look at the corresponding argument to see what integer format is a decimal number. In this case, it is given variable a. So it prints the decimal representation of the number 42 in the location in the string where the %d is. The next call to printf has two %ds. The first refers to b, the next argument after the string which is 7, and the second of these refers to a + b, which is evaluated like any other expression. So it's 42 + 7 which is 49. So the output is b is 7 and a + b is 49. We return 0 and exit main. Another important thing to know about printf is escape sequences. An escape sequence begins with a backslash. The most common one is \n which means new line. This printf call has two \ns. So you should print two new lines after Hello World. This statement declares and initializes b to 7. This printf call has a \t in it which means a tab, is useful for lining up output. The output is, my answer is tab 7, we return in exit main. This introduction has shown you a few uses of the printf function and you'll see more later in the course.