Linux itself is not a fully fledged operating system as most people would expect it.
Since Linux has to work on servers and microchips as well as on desktop PCs, lots of stuff is not shipped with it.
For example Linux is missing a way to display windows and has no real package manager.
A distro (or distribution) is a predefined set of of software, that makes it easier for a user to use Linux.
This is mostly a window manager or desktop environment like KDE or GNOME, a package manager like apt or pacman and useful software like an office suite, a browser and other stuff.
Distros also exist for servers, the ln they don't include a way to display images, but still have a package manager and other useful stuff preinstalled.
That's of course not all, but maybe gives you a little overview.
Arch is most memy distro out there besides Hanna Montana Linux. It became that way because Arch is super hard to maintain in working condition and became a status symbol to use it in some circles. Now there are couple layers of irony vowen into this meme and I am not quite sure where we are right now.
I just checked steam hardware survey and now I am not sure. SteamOS is most popular due to Steam Deck, and with arch and ubuntu right behind.
Still whats popular is not always the best for starting out.
For begginers I would recommend Linux Mint. If you don't like the start menu or file menager ask in one of linux communities, they would be happy to help.
Appreciate the info thanks mate, I'm not really interested in using it tbh, I was just curious.
My PC gets used to play trackmania during boring meetings at work and not a lot else these days. Simple and easy with next to no thought or maintenance is what I'm after so windows is fine for me.
There are a lot of big ones like Ubuntu, Mint, Debian, Fedora or Arch. Arch is for users with a little more experience. But funnily enough Arch has like child-distributions, that build upon its core. Ubuntu is also a 'child' of Debian an Mint builds onto Ubuntu.
It's kind of like three or four big families, that had lots of children. 😂
(and then there are NixOS, OpenSuse and lots of others, which I forgot)
I heartily commend you for asking, and was happy to see you get a good response.
"What is the most common distro" is not straightforward to shat because of the breadth of users. Arch is one of the more... esoteric... distributions, it will allow you very, very fine grained control of everything - but it also requires you to be able to make those choices. At the other end of the scale we might find Ubuntu and Mint which are far less customizable* but "just work" out of the box and, as such, are obvious choices for users new to Linux or unwilling to invest in "tinkering".
Really, the freedom of choice is overwhelming to many newcomers, and at the same time the strength of the whole system.
*Any distro is very customizable. You can make nearly the same changes to Ubuntu and Arch, it's just that Ubuntu is not designed to make that easy for you.