Ubuntu is still one of the most popular Linux distributions, with a large install base across desktop PCs, servers, and embedded devices. Canonical is about to say goodbye to Ubuntu 18.04, unless you use Ubuntu Pro.
Ubuntu 18.04 LTS, also known as "Bionic Beaver," is set to reach the end of its five-year support period on May 31, 2023. Once this happens, the operating system will no longer receive important security updates or updates to most of the apps in the default software repositories. While Flatpak and Snap-based applications may still function, they could begin to malfunction unexpectedly.
Released in April 2018, Ubuntu 18.04 replaced 16.04 as the new Long Term Support (LTS) release. For users transitioning from 16.04 (which Canonical encourages users to do), this release saw the switch from the outdated Unity desktop to GNOME Shell, a reworked login and lock screen, and an improved Settings app, among other changes. Furthermore, Ubuntu 18.04 LTS served as the base for numerous other distributions, including official derivatives such as Lubuntu 18.04, and third-party spins like elementary OS 5.0 Juno.
Consider upgrading your desktop PC or server from Ubuntu 18.04 LTS to Ubuntu 20.04 LTS or 22.04 LTS. While security updates will continue to be provided for Ubuntu 18.04 until April 2028, this is only applicable to systems enrolled in Ubuntu Pro. Ubuntu Pro is primarily aimed towards companies and other organizations that have a slower upgrade process, but it is also available for free to personal and small-scale commercial users on up to 5 machines. If upgrading is not possible, you can refer to the official FAQ for guidance on signing up for Ubuntu Pro.
Source: Ubuntu