Debian and Ubuntu are the most influential Linux distributions ever. Of the 290 active distributions currently listed on Distrowatch, 131 are derived from Debian, including Ubuntu, and another 58 are derived directly from Ubuntu -- roughly two-thirds. Yet the experience of using them differs in just about every aspect. Consequently, choosing between them is no easy matter.
Asked to explain the difference between the two distributions, most users would describe Debian as an expert's distribution, and Ubuntu as a beginner's. These characterizations are partly true, but exaggerated. Debian's reputation rests on its state over a decade ago, and today Debian allows as much hands-on control as each user chooses. Today, it would be better described as a distribution for all levels of users, provided that they are willing to do their own maintenance. Extensive help on the Debian wiki makes this do-it-yourself philosophy less formidable than it might first sound.
Similarly, Ubuntu is really its design team's conception of easy. Should your work habits not be compatible with that concept, you may find Ubuntu less easy to use than advertised, especially if you prefer not to have every choice made for you.
Still, although Ubuntu is derived from Debian, their differences are marked. From installation and desktop to package management and community, what everybody thinks they know about the two may be wrong, or at least in need of heavy qualification – all of which makes choosing which is right for you a difficult process.
Your distribution of choice may depend on your hardware. Debian currently develops for 10 hardware architectures, ranging from standard 32 and 64 bit Intel to Arm and PowerPC, with several architectures having been dropped recently due to a lack of developers to keep them current. By contrast, Ubuntu supports 32 and 64 bit versions as computer desktop environments, and is developing Ubuntu ARM for mobile devices.
Both Debian and Ubuntu installation images are available in a number of choice. You need to search the mirror repositories to find a complete Debian image, but both Debian and Ubuntu are available in torrent downloads and network images – that is, minimal images that complete installation by linking to online software repositories.
Both offer long term support images, with Debian's being supported for three years after they are replaced by another release, and Ubuntu's for five years after their release. One possible consideration is that Ubuntu's long term support is only guaranteed to cover the main release, and not necessarily all flavors and remixes (see below).
Another consideration is the installers for each distribution. Ubuntu's standard installer is designed to require a minimum of user input to keep installation simple and as fast as possible. However, like any Linux installer, Ubuntu's installer tends to assume that you understand a few basic concepts, such as disk partitioning and passwords. Should you encounter problems, you can try the expert mode installer – a lightly re-branded version of the Debian Installer.
The Debian Installer clearly has other priorities. Its graphic version is a GUI that differs little from the text-based installer, offering no advantage except comfort for those nervous about the command line.
Contrary to Debian's former reputation, it can usually be installed by following the online instructions and accepting the default settings for each stage. However, if you choose, you can make individual choices at every step of the installation process, substantially increasing the required time. Instead of catering to inexperienced users, the Debian installer accommodates all levels of users. It may not be pretty, but, short of compiling your own packages, you are unlikely to find a more flexible installer.
During installation, Debian offers a half dozen choices of desktop environments. By contrast, Ubuntu used to default to Unity, a desktop of its own design, but, as of the upcoming 17.10 release, will default to GNOME.
However, the choices available during installation are only part of the story. Ubuntu provides alternative flavours and remix images such as Kubuntu for KDE and Xubuntu for Xfce, as well as in its repositories. These variations share the underlying GNOME technologies with the standard-issue Ubuntu, and may or may not sync with official releases of their desktop environments, give or take a few weeks. Whether the latest version of Unity will be available in the next Ubuntu release is uncertain, although a breakaway project has been announced to continue development.
In Debian, the choice of desktops is roughly the same, but the teams developing them are less separate from standard Debian. The timeliness of these releases varies, so expect to take some time in online searches to find what is happening with any team whose results may interest you. Neither Linux Mint's MATE nor Unity are available from Debian's repositories.
Except for Unity, most software written for Ubuntu is also available for Debian. Software written for Debian is almost always available for Ubuntu, because Ubuntu draws its packages from Debian's repositories. Depending on where Debian is in its ponderously slow release cycle, Ubuntu's software is usually more current than Debian's, but as a tradeoff, Debian's is more thoroughly tested and stable -- not just more so than Ubuntu, but more so than almost any other distribution.
A warning, though: do not assume that a common origin makes packages cross- compatible. While many packages can be installed on both Debian and Ubuntu, about twenty percent of Ubuntu's packages are developed by the distribution to fit Ubuntu's special need, and stand a large chance of being incompatible with Debian due to differences in name and file locations. Now that Ubuntu will be using GNOME again, the number of incompatible packages may decrease, although that is currently uncertain.
Administration and Package Management
Unsurprisingly, both Debian and Ubuntu encourage the use of a root account for administrative purposes, and restricted accounts for everyday computing. However, the chosen security models are different.
In Debian, by default users do administrative work while logged into the root account, then -- ideally -- logging out again as quickly as possible to reduce the period of vulnerability. Ubuntu, though, obscures the root password, instead using sudo, and allowing at least one user to enter their own password to issue administrative commands. To use sudo on Debian, you need to leave the password for the root account blank when installing.
Which of these security models is preferable is frequently debated, so you should search for a discussion on the subject so that you can decide which you prefer. You might also look up the options for sudo and decide on a sudo set up altogether different from Ubuntu's and Debian's defaults.
Debian's packages are divided into three main categories: Unstable, Testing, and Stable. A new package enters stable, and transfers into Testing when it has been debugged. When an official release is prepared, the current packages in Testing under further quality assurance, and eventually become the new Stable.
In recent years, other repositories have been officially or unofficially added, such as Experimental, Old Stable, Security, Backports ,and Update. However, users should pay most attention to the three main repositories.
The advantage of Debian's system is that you can choose a position anywhere between two extremes: rock-solid stability, at the cost of older versions of software, or cutting edge, at the cost of less robust software and, at times, drastic changes in technology that can cripple an unwary user's system. The choice can depend on whether you upgrade a core component, such as the Linux kernel, or a self-contained utility with its own libraries that affects nothing else when disaster strikes.
By contrast, Ubuntu derives its packages from Debian Unstable or Testing. Instead of being organized by testing status, Ubuntu's repositories are organized by other criteria. Main contains software supported by Canonical, Universe software supported by the Ubuntu Community. Restricted contains proprietary drivers, while Multiverse holds software with copyright or legal limitations.
Another major difference is that Debian is much more dedicated to software freedom. By default, it installs only free software, and its installer even goes so far as to offer a kernel free of proprietary firmware. If you want nonfree software, you have add the Contrib and Nonfree sections to each repository.
In Ubuntu, the distinction between free and proprietary is much less clear in Ubuntu. While Debian discourages the use of proprietary software (although allowing users to make their own choice), Ubuntu encourages users to install proprietary software in order to have a computing experience comparable to that on any commercial operating system. You can get the same experience on Debian if you are willing to work, but Debian makes clearer that you do so at the expensive of software freedom.
Not every user cares about the community that makes their distribution But for users who may become involved with developing, Debian's and Ubuntu's communities may also be a factor in their choice.
Debian is famous -- even infamous -- for discussing everything in great detail. Especially contentious issues can even go to a general vote. Every year, Debian elections its Leader using a Condorcet method, which, in contrast to the system of majority votes that prevails throughout North America, determines the winner by comparing the results of each candidate against those of the others, and is generally considered one of the fairest methods of determining election results.
In recent years, Debian has mellowed, but the discussion can still sometimes become a free-for-all, especially on the debian-legal mailing list. In the past, Debian has been described as a hostile environment for women, and, several years ago, the debate on replacing init with systemd became so intense that a couple of veteran developers resigned rather endure abuse.
At the same time, Debian is a meritocratic democracy, with all official developers having the right to vote on the Debian Leader and other issues. Although appointed positions can sometimes be a source of power, in general Debian officials lead more by suggestion and diplomacy than direct command.
Ubuntu contrasts with Debian in that it has a Code of Conduct for community interaction. Until recently, Ubuntu's community manager was Jono Bacon, who literally wrote the book on The Art of Community, and made considerable effort at conflict resolution. In addition, a Community Council and Technical Board is partly elected every year.
However, Ubuntu's democratic appearance is not quite what it appears. Ubuntu's founder, Mark Shuttleworth, sits on both governing boards permanently, and casts the deciding vote. Shuttleworth – and, at times, his Canonical representatives – also have veto power over the community, which in the past has caused several user revolts.
Deciding Between the Debian and Ubuntu
Beginner or expert? Platform support? Ease of use or control? Cutting edge or stability? Free or proprietary? Outspoken but democratic, or generally polite or controlled? As you can see, choosing between Debian and Ubuntu comes down to what is important to you.
Before you choose one distribution over the other, decide where you stand on all these dichotomies. Or perhaps some of these divisions are more important to you than the others.
Or, should you appreciate Ubuntu's simpler installer, but find the distribution not to your liking, investigate Linux Mint, another Debian derivative that many prefer over Ubuntu -- and that is definitely a topic for another day.
In the end, no matter how you decide, you can hardly go too far wrong. For all their differences, Debian and Ubuntu did not become leading distributions in free software by chance. Their joint dominance suggests that either is a valid choice, so long as you understand your priorities.