Program

What is a Computer Program?

A computer program is a list of steps that a computer (a CPU) has to perform. In other words, a program is an algorithm executed by a computer. We also use the term "program" to refer to programs that you can download, install, and run in your computer, e.g. a desktop application or a smartphone app is a program. These sorts of programs can appear in the form of executable files (with .exe extension in Windows).

Every time your computer is displaying something on the screen, a program is running. Even when you just turned it on, and some white text shows up in a black screen, that's a program. The first programs to run is the BIOS (Basic Input Output System). The BIOS looks into your SSD or HDD to see if you have an operating system, such as Windows, and if you do, the BIOS program starts the operating system program. Then the operating system program starts several other programs, which are what shows you the start menu, your files on the desktop, etc. Then when you click on a file, those programs start other programs to display the files. In other words, from the instant you press the power up, you have a long chain of one program loading the next program in your RAM memory to be executed by the CPU.