There are two ways to check which version of Ubuntu you are running. You can either check from within Unity, or put in a short command in the Terminal.
In Unity
Unity is the default desktop environment for Ubuntu 12.04 (Precise Pangolin) and later.
- Click on the "cog" in the upper-right portion of the screen.
-
Select the option: About This Computer
In the Terminal
This method will work no matter which version of Ubuntu or desktop environment you are running.
-
Open the Terminal (keyboard
shortcut: Ctrl+Alt+T) -
Enter the command lsb_release -a
Your version will be shown on the Description line.