Of course, not everybody can compile an operating system from scratch and this is why there are people who do it for you. Each variety of Linux is called a distribution (or a distro) for short. Linux distros are compiled for you by the distro authors/maintainers, who have selected the packages for you to use – you just download the distro and install it (and hope that it works!).
All distros share the same Linux kernel and many of the packages are also the same among distributions. However, each distro is built for a purpose – i.e. to be used as a desktop system, or as a server platform, or as a security stronghold, etc. and this is why the creators of the distro select different packages to include in it. Also, many distros come with a preselected desktop environment (i.e. Gnome, KDE, or other), though as a rule you can always get a distro and if it doesn't include the desktop environment of your choice, you can always install it on your own.
Now, after this necessary introduction, let's move on and see which flavors of Linux that are common. The categorizations below are not mutually exclusive and as you will see, some of the most popular distros fall in more than one category.
RedHat-Based
The first classification of Linux distros is according to the mother-distribution they use. Here the two most popular are the RedHat-based distros and the Debian ones. RedHat and Debian are two of the most popular Linux distros of all times and it is not surprising that they have so many offsprings. One of the most popular offsprings of RedHat is Fedora, which is basically RedHat for the desktop, while RedHat itself is more of an enterprise platform.
CentOS is another very popular Linux distro, which is based on RedHat. However, there is formally no connection between them. CentOS is especially good for shared hosting and that is why for many web hosting companies this is the Linux distribution they choose (and stick to).
Debian-Based
Debian is another very popular Linux distribution and it has even more offsprings than RedHat. Ubuntu, which is currently considered the most popular Linux distribution, is Debian-based. Xandros and Damn Small Linux are two other very popular Debian-based distros. Some of these Debian-derivatives have derivatives of their own – for instance Linux Mint, which is also a very popular Linux distro is actually a derivative of Ubuntu.
Slackware and Followers
Slackware is another Linux distribution with traditions. The tech community loves Slackware a lot. Slackware doesn't have as many offsprings as Debian but still there are at least ten distributions, including the relatively popular Slax and Zenwalk, which originate from Slackware.
Live CDs
In addition to the distribution on which a Linux download is based, another division is between downloads, which need to be installed and Live CDs, which are downloads that can be run right from the CD/DVD (i.e. no installation is necessary). The Live CD trend started relatively recently but these distros are very popular because they are so easy to use.
Many distributions have a Live CD version and a normal version. For instance, both RedHat-based and Debian-based distributions come as both a normal version and a Live CD.
On the other hand, even those Linux distributions, which are mainly a Live CD (i.e. Knoppix or Ubuntu) generally have an option to be permanently installed on the hard drive. Live CDs are great when your operating system is messed up and you can't access it the normal way – you just boot from the Live CD and use the applications from there. Of course, Live CDs can be used permanently, not only in emergencies but in this case, you'd better install them on the hard drive.
Desktop Linux Flavors
Another division of Linux distributions is according to their purpose. Basically, there are two groups – desktops and servers.
While it can be said that in comparison to Windows, Linux is still behind as a desktop operation system, the desktop department of Linux is getting richer and richer and many Linux distros provide everything a user needs – i.e. an office package, web browser, multimedia functionality, image processing, etc. Some of the most popular Linux desktop distributions are Ubuntu, OpenSuse, Mandriva, and Xandros – these are just some of them, there are many, many more.
Linux for Servers
Traditionally Linux is a server operating system and this is why it is not surprising that there are so many distributions, which are aimed mainly to be run on servers. CentOS and RedHat are the two best examples but there are many, many others. For instance, Debian and Slackware are also frequently found on servers.
Security Enhanced
One of the flavors of Linux, which deserve special attention when web hosting is concerned, are the security enhanced distributions. These distributions include various tools for network testing, penetration testing, and other security checks. Some of the most notable examples are SELinux and BackTrack but there are also a couple more, which deserve attention.
This article is a very brief introduction to Linux flavors. Since there are so many of them, it is not possible to mention them all. The distros listed here are just some examples of the most popular ones. And yes, – even Linux maniacs can't list all of the available distributions and if asked, they might omit 1-2 of the Top 20 (if there were Top 20, of course).
What is more, new distributions are released all the time, so if you have nothing else to do as a full-time occupation, keeping track of new Linux distros and changes to existing ones could keep you busy most of the day. DistroWatch.com is one of the sites, where you can find up-to-date information about new releases and read more detailed reviews about the distros of interest to you, so if you want to know more about the Linux flavors, this site is a great starting point.
Commented by: M, 29 October, 2009
Small article but enough information.......thanks!