This is a series of tutorials about working with files.

One special type of file is a program file.

Program files usually have an ".exe" extension. In contrast to, for example, text files that you create with Notepad, program files do not contain data. Instead they contain instructions to the computer. The computer executes these instructions. The instructions tell the computer what windows to put on the screen, what to do when the user enters keystrokes, and so on.