Have you ever forgotten which Ubuntu version you are using? If it's true here you will find methods how to check Ubuntu version that you are curently running.
1. Use lsb_release commandSimply run from command line:
2. Find Ubuntu version inside /etc/issue fileSimply edit or cat issue file like below:
3. Check ubuntu version in lsb-release file
cat /etc/lsb-releaseThose are most commonly used ways to check Ubuntu version which your system is running from the command line level.