Each Debian release has a name, probably supposed to help remembering them. I’m running bullseye is much easer than, I have Debian 11.3. However, with names, it’s much more difficult to tell which release is newer, or how many releases are between two releases. The situation is exacerbated by Ubuntu, which although based on Debian, comes with its own release name aliases. This article summarizes the release names of Debian and the corresponding Ubuntu LTS releases.

Date Debian version Debian release Ubuntu version Ubuntu release
not yet 12.0 bookworm 22.04 Jammy Jellyfish
2021-08 11.0 bullseye 20.04 Focal Fossa
2019-07 10.0 buster 18.04 Bionic Beaver
2017-06 9.0 stretch 16.04 Xenial Xerus
2015-04 8.0 jessie 14.04 Trusty Tahr
2013-05 7.0 wheezy 12.04 Precise Pangolin
2011-02 6.0 squeeze 10.04 Lucid Lynx

The related versions of Debian and Ubuntu haven’t been selected carefully. The table just shows the corresponding LTS Debian releases, although are are many more intermediate releases as well.