Clearing
If, for whatever reason, your chosen Universities decide they can live without your presence, all is not lost. The UCAS clearing system is your opportunity to gain a place on a university or college course, starting the autumn after your exams finish.
In basic terms, once Universities know which courses have not been filled they advertise their spare places (in newspapers like The Times, Telegraph and Guardian - if you're a committed Sun reader then perhaps you should, just this once, break the habit of a lifetime...).
If you find a course that meets the grades you've got, the clearing process is what you have to go through to get that coveted place...