If you apply through a college they submit your predicted grades along with a reference to UCAS before the deadline, if you are applying yourself I'm not 100% as to what you need to do, but I am presuming you need to send off similar information. You receive offers from universities by the 20th May.
These offers could be conditional, subject to what results you get or unconditional. You need to select a firm choice and insurance choices by June.
You get your results in July, these would be sent directly to UCAS by your awarding body and you either meet your conditions for your firm choice or insurance choices. If so, great.
If your results fall short and you don't meet the conditions of your offer/s there are multiple potential ways forward, including:
- Being offered a foundation year.
- offered a slightly different course with lower requirements.
- rejected outright, then you would need to go through the clearing process.