Ubuntu 21.10 (Impish Indri) It was released last year, and after a few months of service to all users who opted for this distro, it will now reach the end of its useful life. You will still be able to use it beyond that limit, but it will pose significant security risks. And it is that on July 14, 2022, this system is scheduled to be abandoned, at which time the support ends, so it will not receive any more updates to correct bugs or patches to cover vulnerabilities. Therefore, you should install Ubuntu 22.04 LTS if you want to continue to enjoy long-term support.
Write down that date, and try to change the version before that day in order to be always up to date with updates. And this is more important than some people think, since it is not only about new improvements that can be received, but uncorrected bugs can affect your productivity and even imply the loss of important personal or business data, and Vulnerabilities represent security holes that can facilitate cyber attacks and information theft, which can have a very high cost for companies.
So, on July 14, 2022, in a couple of months, Ubuntu 21.10 will reach its EOL, while Ubuntu 22.04 LTS (Jammy Jellyfish) not only does it continue to receive updates, but it will continue to do so for the next 5 years, until April 2027 specifically. That means having the latest patches for a long time, it means stability, security, robustness. Time to change! And if you prefer the provisional versions, you should know that Canonical has already started the development of Ubuntu 22.10 (Kinetic Kudu), but it will not arrive until the end of October, specifically on October 20 of this year. Therefore, if you decide to wait for that, do it at your own risk, since you will have a few months without support...
By the way, this also valid for the rest of Ubuntu flavors. So if you have any of these distros, you know that you should switch to the LTS version as soon as possible: Kubuntu, Lubuntu,...