When you're trying to decentralise your technology, one of the key things to consider is your computer's Operating System (OS).
Your OS is the most important piece of software in your computer, that makes it possible for your programs to use your hardware.
Usually when people buy a computer, an OS comes pre-installed. For most computers this is Microsoft Windows, although Apple computers have their own OS called MacOS.
However, it is possible to replace the pre-installed OS by choosing a different OS yourself and installing it. Linux OSs are the most popular alternative.
Why switch OS?
Windows especially pushes very strongly to centralisation. Forcing users to create an online account, controlling when their computer updates and what is installed, and sending data about the computer's usage back to Microsoft all being prime examples. This leads to a feeling that your computer belongs to Microsoft instead of you.
People who want to take back control often choose to install a different OS.
What are distros?
When you first look into installing Linux, you'll see a lot of people telling you to choose a "distro", short for "distribution". This is because Linux, technically speaking, is only one part of the OS. Packaging it together with other software is what turns it into a full OS. And there are different sets of software you can choose, each called a "distribution".
Choosing a distro is not as big a deal as it sounds and should not discourage you. The main things to consider are: do you want frequent small updates to keep your OS on the cutting-edge (rolling-release model) or infrequent large updates to keep your OS stable (fixed release model).
Note that the "look and feel" of a Linux OS comes from its "desktop environment" (DE), not directly from the distribution - if you find a DE you like the look of, there are usually many different distros that can use that DE.
Some examples of Linux OSs
- Linux Mint: Fixed release, DE choice of Cinnamon, MATE or XFCE
- CachyOS: Rolling release, many different DEs offered during installation (KDE is default)
Addendum: Free Software
As requested in the comments, I'm adding a little text to mention that Linux is Free/Open Source Software. You don't need to understand this to use Linux, but you may be interested in the topic. The free part refers to freedom, rather than "free of charge" (although most Linux distros are also free of charge). What this means in practical terms is that the source code of a program can be read by anyone to verify that nothing nasty is included, and also forked to create a new program if the direction of the original diverges too far from what people want. These traits are particularly useful for an operating system, since it has complete access to your computer and its files.