Hello,
Microsoft’s decision to end support for Windows 10 aligns with its standard lifecycle policy for operating systems. Windows 10 was originally released in 2015, and Microsoft committed to a 10-year support lifecycle, which means support will officially end on October 14, 2025. After this date, Windows 10 will no longer receive feature update or security update. That doesn't mean you cannot use Windows 10 after that. You can use it for as long as it runs.
Just like when Windows 8 and 7 ended support, for business users, extended security update will be available to buy them some time to trasition. For home users, Microsoft recently also annouced that extended security update will be available as well.
In addition, you can use third party security program of your choice if you don't want to move to Win11.
As for 12, Microsoft has not officially announced Windows 12's release date yet as of now.