Windows 11 will be released later this year. However, it might not be available to everyone. Computers need to have a fairly modern processor and something called TPM 2.0 This is a security feature that newer computers have but older ones don't. The upgrade is expected to be free for those who can (and want) to install it.
This isn't the end of the road for older computers. Windows 10 will be supported with all updates by Microsoft until October 2025. Also, we might find that Microsoft will review hardware requirements before the Windows 11 release date.