This chapter teaches you about the following:
Computing is all about inputs and outputs. Data goes in and data comes out. Without inputs and outputs, nothing would happen and nothing would get done. A word processor doesn't begin to do anything until it receives input from the user (usually in the form of characters generated by keystrokes), and this then leads to an output (it is outputted onto the screen and subsequently to paper or electronically).
AlertThis is for outputting information.
ConfirmThis outputs information and allows the user to input a choice in the form of a yes/no question.
PromptThis outputs some information and enables the user to type in a response to the output.
alert(), confirm(), and prompt() are actually all methods of the browser's Window object.