All programs use variables to hold pieces of data tempararily.
For example, if at some point in a program you ask a user for a number, you will store it in a variable so that you can use it later. For example, you might declare one variable to have a type that allows it to hold numbers, and another variable to have a type so it can hold a person's name. Certain languages don't have these requirements. In this program we have declared two variables named width and height . We have declared their type to be int .