It means that there will be no more official security updates and bug fixes for the operating system launched 13 years ago by Microsoft.
Statistics suggest 20-25% of all users have stuck with XP despite the fact that there have been three major releases of Windows since its debut in October 2001.
German AV-Test group said, "Malware writers go for the low hanging fruits because it's a lot easier to infect systems running on an old Windows XP operating system compared to brand-new Windows 8.1, with all its built-in security features", particulkarly as Windows XP users topped the list of victims cyber-thieves targeted.
Whilst Microsoft have provided Windows Upgrade Assistant to check if your PC meets the system requirements for Windows 8 / Windows 8.1 very few older computers are able to run.
However as Windows 7 is still supported, then perhaps the the Windows 7 Upgrade Advisor might be a better option for some.
Lets all ignore Vista
Hope this helps any one still with XP