How to check UBUNTU version?
When I was learning Ubuntu it was very difficult to know Ubuntu version.
Refer following step which can help you to know Ubuntu version.
Step 1: Open the terminal.
Step 2: Enter the lsb_release -a command.
Step 1: Open “System Settings” from the desktop main menu in Unity.
Step 2: Click on the “Details” icon under “System.”
Step 3: See version information.
Or
Use this in the terminal to show the details about the installed Ubuntu "version":
lsb_release -a