A vaccine introduces a small amount of an inactivated virus into your system, which triggers your immune system to build immunity against that virus. So if you get a larger amount of the virus in the future, your immune system already recongizes it and can respond.
But the Covid-19 vaccines don’t do this. They do not trigger your immune system to recognize the Covid-19 coronavirus. They do not prevent you from getting infected with Covid-19. They do not prevent you from spreading Covid-19. If you get Covid-19, despite being vaccinated, you still have to take anti-viral drugs and other treatments.
So what do the vaccines do?