Hello I switched to linux recently and I tried some different distros. The fact is that all of them except one are debian based. I used Linux mint, pardus, manjaro (the only non-debian distro) and Astra linux. Now because I don't like Arch systems because I prefer stability over bleeding edge I became interested in RH based distros. My questions are:

1- What are the differences between debian based and Red hat based distros????

2- Which RH based distro would you suggest me ?

I thought about installing open mandriva or oracle linux. Take into consideration that I am a newcomer and don't know much but, I can get things done if I concentrate and work on them.

PS: (Desktop user).

Fedora is an obvious choice for desktop user. But it's rather bleeding-edge. Open Mandriva (actually, its granddaddy, Mandrake) diverted from RedHat in many ways long ago, it cannot be considered a RedHat-based distro. CentOS is stable, but it's for servers, not for desktop. Same for Oracle. Better stay with a Debian-based distro on desktop.

The main difference between the Debian and Red Hat families is the package managers.

When I started out on Linux, I tried a variety of distros, but back then, there really were big differences between distros, not so much these days.

It really just comes down to which package manager system you prefer these days.
The other things to consider are whether you prefer an all encompassing desktop like KDE, a medium desktop like XFCE, or a system based on a Window Manager, such as IceWM of Fluxbox.

(My usual recommendations are MX Linux for a mid weight distro, or AntiX for a lighter distro, both are based on Debian.)

One big difference between Debian (not necessarily Debian-based distros) and RHEL-derived distros is that RHEL and Centos consciously limit your choice or at least have a default way of doing things. For example, the only timeserver in Centos 8, as far as I know, is chrony. The only(?) web server is Apache's httpd. And so on.

Debian on the other hand seems to have the philosophy of providing as much choice as possible. For time services, it offers chrony, ntpd, open-ntp and the systemd timeserver (at least).

For a newbie, limitation of choice might be a good thing. While the distros in the RHEL universe are more server-oriented, they do include fully-featured desktop software. I can't imagine that Red Hat employees have anything except RHEL, perhaps Fedora, on their PCs.

You forgot to check out SLES/OpenSUSE, by the way. It is not Debian-, RHEL- or Arch-based. I don't know it well enough to have an opinion, though.

Already mentioned, the package format (rpm) and manager. Between the several derivations (CentOS, Scientific Linux, Oracle Linux and of course the forerunner: Fedora) there are differences too in the tool to manage the package manager: yum, dnf, etc.

Although (open)SUSE and Mandriva are rpm based too, they're not really deratives from RedHat anymore, the split occurred too long ago.

And Red Hat itself (RHEL) is commercial: support and updates can only be gotten if you pay for them (get a subscription for updates etc).

Another difference between especially ubuntu and RHEL/CentOS/Scientic Linux/Oracle Linux is that they are really conservative, in kernel and available packages (and versions).
RHEL and its deratives aim for stability and reliability and not the newest packages or versions. This is different for Fedora, it runs ahead as a sort of testbed.
For instance RHEL 8 (and its deratives like Oracle/CentOS 8) is based on Fedore 28, but Fedora in the mean time already has released version 31

All of the above is good information, but I do want to correct one thing.
CentOS does make a decent OS for a workstation or platform. It is very conservative (as is RHEL) and you have fewer options and older software, but the distro team backports security patches and updates to keep it quite secure. (It runs about a week behind RHEL with security, no more, and about 6 months behind on releases: based upon the last time I ran it in a production/testing/UAT/QA environment.)

I have run it mostly on servers, because I wanted newer software versions and features, but others have used it for laptops for development.
It can be a solid option.

Now to another question: what do you want to USE it for? What you do, what you need running, and how you use the hardware will determine how happy you would be with CentOS as your choice.

I notice that even today there is still a wider variety of packages for the Debian based distros over the Fedora based distros. There is also the obvious question of the package format itself, but if you are not building anything yourself, then that is not relevant. Other than those two, I cannot think of much difference except that Fedora based distros are the ones that screwed us over with systemd and spread it through non-technical means, particularly personal attacks and appeals to novelty.

However, for me, those first two points, the package format and pre-packaged software availability, combine to keep me on APT-based distros after having used RPM-based distros on and off over the years. Thus I'd recommend looking at Linux Mint or Ubuntu for the desktop or Devuan or Ubuntu for the server.

A few months back one of the LQ users posted this, may be it will help you?

https://distrotest.net/

From the site:
BTW: CentOS does have desktop environment, and I used to use it on my laptop for a while.
Switched to Fedora because it tend to have better drivers support for newer hardware

Did you ever look at the epel (Extra Packages for Enterprise Linux) repo (which is geared towards RHEL/CentOS) and i.e. the openSUSE Build Service (build.opensuse.org) in which many more packages for rpm-based distro's are available? I quote from the openSUSE site
OK, the SUSE type of packages is most common, but others including Fedora, RHEL and even Debian and Ubuntu ones are available there.

And as for desktop: CentOS (etc) do have KDE/Plasma 5 and Gnome 3 available, standard.

nice link.

The reason Fedora has better driver support than CentOS is the faster deployment of newer kernels. CentOS is the open license for RHEL. RHELvX is 1 single kernel for its entire life. Fedora updates roughly every 15-18 months and each new iteration is built on a new kernel. This leads to more issues but also better hardware/software support.

For a workstation as a new user (talking to the OP) I would check out that link and play around.

Fedora is built on newer, but not the most bleeding edge software/hardware out there. As a result you get some nice new toys to play with, but some of those can lead to a bit of instability. Has been my desktop of choice since roughly 2011. I am now moving back to Ubuntu for other reasons.

Ubuntu has their LTS (Long Term Support) that is often used as a server and their bleeding edge releases. As this is a Debian fork you can get stable or testing forks too. To me this is a great place for a new Linux user to start. While Ubuntu does several things I personally do not like with their distro, it is still a great place to get your feet wet.

OpenSUSE, as long as you have some good hardware, it is amazingly refined with some of the best GUI tools I have ever used. If you have the hardware that will run it (rather new with plenty of RAM and a well supported GPU) this is another great place to start.

If you have time on your hand and really want to get your hands dirty, so to speak, check out Gentoo Linux. Very fun OS to play with and will force you to learn the ins and outs of linux. Very steep learning curve.

Thank you for the reply
I use it mainly with office programs, internet surfing, to read books about linux and a little bit of gaming. The games I play are not last generation games with super fancy graphics (CSGO and METRO 2033 are the heaviest I think) and my hardware even if it dates back to around 2014/2013 it is very powerful and never had issues with my hardware at all even after intense usage. Also another characteristic I want is a distro with which I can learn a lot about the system nut not complicated to use this is why I thought about open mandriva because people say that it is easy to use. Oracle linux, I thought about that because I think it is the most stable distro ever and It is almost impossible to break something in it but, people told me that it is not good fore desktops.

Thank you again

Thank you for the reply man

One question: Isn't (open)SUSE a fork of slackware or I am wrong ? They use zypper not yum or dnf.

I thought about fedora but I heard that it breaks quite often, is that true ?

It started out as a Slackware fork but it soon drifted away from its roots. They use rpm packages, which they obviously borrowed from the Red Hat family.