This is my newest post in my series about operating systems. Yes, it was last updated in 2019 – I’m a hobbyist blogger. This is a post about the command line, a computer topic, but it is for educating a non-technical (but tech-curious) audience. Most of the programmers in my audience will already know everything I have to say, and may be bored by some explanation of things they already know, though I intend to discuss some technical details of how computers work.

In previous posts, we discussed historic operating systems and where various OS features come from, but we only gave a brief overview of how they worked. Now that we have a modern operating system’s full complement of features, we can look at what components need to exist in a modern operating system to get those features. As discussed with MS-DOS, an operating system, even today, is partially code, and partially conventions, like file formats or rules of good behavior – the difference being, that modern operating systems have more ability to enforce some of these conventions.

We use operating systems all the time in our life, whether designed for a computer, a phone, or for a server we’re more indirectly interacting with, but a lot of people don’t know very much about what connects the different systems we use, and what makes them distinct. We discussed fundamental concepts of operating systems in the last post, so in this post we will discuss how some of the same concepts apply to modern operating systems, going over them one at a time.

A user of modern technology hears the term “operating system” thrown around a lot. Most people can name a few examples: Windows and macOS on workstations and laptops, iOS and Android on phones. Some people might even throw in Linux or Unix or ChromeOS. Most people also understand that a program or a game or even a sufficiently advanced website might work on some operating systems but not others, and might require different versions for different operating systems.