Ubuntu Versions and How It versioning

Ubuntu is based on Linux operating system. The developing started in 2004.Ubuntu releases are made semiannually by Canonical Ltd, using the year and month of the release as a version number. Usually they releases twice in a year in the month of April and October. So their versions are starting with year and month.

For E.G. 
They release a version in the year 2012 in the month of October means, the version should be 12.10.  12 is taken from the released year and 10 refers the month October.

Version Code name Release date Kernel Version

4.10          Warty Warthog 20 October 2004 2.6.8
5.04           Hoary Hedgehog 8 April 2005 2.6.10
5.10  Breezy Badger        13 October 2005 2.6.12
6.06 LTS    Dapper Drake        1 June 2006 2.6.15
6.10          Edgy Eft                  26 October 2006 2.6.17
7.04          Feisty Fawn            19 April 2007 2.6.20
7.10          Gutsy Gibbon         18 October 2007 2.6.22
8.04 LTS  Hardy Heron          24 April 2008 2.6.24
8.10          Intrepid Ibex          30 October 2008 2.6.27
9.04          Jaunty Jackalope     23 April 2009 2.6.28
9.10          Karmic Koala        29 October 2009 2.6.31
10.04 LTS Lucid Lynx             29 April 2010 2.6.32
10.10         Maverick Meerkat   10 October 2010 2.6.35
11.04         Natty Narwhal        28 April 2011 2.6.38
11.10         Oneiric Ocelot        13 October 2011 3.0
12.04 LTS Precise Pangolin     26 April 2012 3.2
12.10         Quantal Quetzal      18 October 2012 3.5
13.04         Raring Ringtail        25 April 2013 3.8


LTS - Long Term Support
8.04 supports still April 2013
10.04 supports still April 2015
12.04 supports still April 2017