With the release of Ubuntu 16.04 LTS you may feel that it is time to update the older Ubuntu 14.04 LTS to the latest version.
If you do not get automatically notified by the Software Update Manager on Ubuntu 14.04 LTS, you can manually trigger the Upgrade to Ubuntu 16.04 LTS by entering the following command in the Terminal:
sudo update-manager -d
When you now hit the return/enter key and enter your user password, the Update Manager application will open after a few seconds.
It will first double-check your Ubuntu 14.04 LTS is up to date and do all necessary updates first.
After that it will display a prompt asking you if you want to upgrade to Ubuntu 16.04 LTS and what packages will be added, updated, removed or not supported anymore.
Depending on your Internet connection the download and installation of the Ubuntu 16.04 LTS can take some time.