Now it will not be supported any longer.
On April 11 Vista will die.
Vista and Windows 7 are pretty similar so Win 7 is Vista on steroids; and will be supported for a while longer.
So what happens if you continue to use Vista after April 11?
Short answer: Nothing!
Everything will work as before but Microsoft claims that you will be even more vulnerable to security risks and viruses.
If you continue to use Windows Vista after support has ended, your computer will still work but it might become more vulnerable to security risks and viruses.
Now those vulnerabilities are plenty in Windows 8 and 10 too so I guess we need a definition of "more".
If you consider it to be a risk that Microsoft is gathering data about you ..then I bet you are even more at risk with Windows 8 and 10 than with Vista....
Microsoft does not classify risks like that - because they are trustworthy