To check the release or version of Ubuntu you are running, open a terminal window and enter the command shown below.
$ lsb_release -a <enter>
It returns a result like the one shown below:
No LSB modules are available.
Distributor ID: Ubuntu
Description: Ubuntu 12.04.1 LTS
This information is useful, if you need to determine what version of Ubuntu you have and if you have been automatically been upgraded for point releases for the Long Term Support edition you installed on your computer.