The Linux Kernel: What Is an Operating System?

You can think of a modern computer as a complicated system of algorithms all talking with each other all the time. These algorithms exist to simplify some complex process so that the next software developer can write on top of them without understanding exactly how their entire computer works.

You have likely written a Hello World application by now which drew something to the display. But imagine for a second all of the systems which controlled how the electrons from your battery illuminated those particular pixels on your screen. Your motherboard connected your memory and storage to your CPU who's state was temporarily set by your commands in such a way that those particular pixels illuminated in the pattern you expected. You do not need to understand any of that though, to write your code. All you need to understand is the relevant algorithms for your project.

The Kernel is basically the level of algorithms responsible for controlling all of these firmware level systems. It translates programs running on the computer into commands to send to various hardware components. For example, when you plug a mouse to your computer the kernel sees that a new USB device was added. It communicates with the new device over one of many USB algorithms and turns the mouses physical movements to software commands that any program on your computer can understand.

Basically, the kernel is responsible for turning your code into physical states on your hardware devices like the pixels on your screen or the music in your earbuds. The developers who have contributed to The Linux Kernel over the decades have given us a great gift: we don't have to think about have to think about how our computer turns our poorly written code into pixels on screens. There are too many algorithms running on any modern computer for any single person to understand.