When choosing an Operating System to use, there are a number of things you need to evaluate. I will break these down into the following:
What kind of computer will be running it? Will the computer have a lot of power at its disposal, or will it be just powerful enough to handle a very simple and specific task?
What range of tasks need to be accomplished? Can you use the same computer for a great number of tasks, or will the computer be used primarily in a specific setting or for tasks associated with a specific goal. This component is also a significant factor in the first question.
What kind of budget are you working with? Can you afford to use an Operating System that comes with premium hardware? If not, what options do you have? Is it the case that you can't really afford to pay for an Operating System?
What kind of technical skills are expected of the person(s) who will be interacting with the Operating System? If an individual using a machine has the ability to complete all of their tasks using a command-line for instance, is it more effective to deploy a "headless" system? For anyone unaware, a "headless" system is one which uses no screen. Think of a wi-fi router or a server. These don't usually use screens.
Other important considerations are longevity and legacy support. If you need a machine that will last a long time, you may want to use a lighter Operating System, like Linux or (maybe) MacOS. If you don't care as much how long the machine lasts, but it needs to support older software, Windows or Linux are probably your best choices, depending on which software is required.
But what if you didn't have to choose just one Operating System? Say you've purchased a very powerful computer, let's say a 2019 MacBook Pro, and you absolutely have to have support for both Mac and Windows apps. In situations like this, you can set up something called Dual-Booting. On a Dual-Booting machine, you can select which Operating System you want to use when the computer starts up. This way, you can switch between Operating Systems as needed, but with the limitation that you will still have to reboot in order to switch Operating Systems. This is commonly done with desktop Linux systems, as many Desktop Linux users still need Windows for certain tools and software. As an example, Linux is often used by college students, but the Lockdown Browser (which requires a tremendous level of access to your Operating System) does not work with Windows. As a result, many college students will use an unactivated version of Windows just to run Lockdown browser, while keeping the rest of their work on their Linux partition. Partitions are a more complicated concept beyond the scope of this blog. Suffice to say that each Operating System in this example will use one or more partitions, but only one of which actually matters from a user's perspective.