Yes it is the end for the extended support of Windows Server 2003.
All Clients especially ones that process Financial transactions, medical data, Legal data, etc.. should not be utilizing Windows Server 2003 as Microsoft will no longer be supporting it.
While it's true that you can keep using your Server (2003) after support ends, we don’t recommend it. For starters, it’ll become five times more vulnerable to security risks and viruses, which means you could get hacked and have your personal information stolen. And even if you escape attacks, over time, the security and performance of yo