If you are even vaguely thinking of doing a course in the UK you need to understand how the UCAS system works. It is entirely different to the CAO with a very different process and timetable. If this is for you then read on.
In a nutshell UCAS is sort of a middleman in the application process. Universities post online the requirements for students, course options and financial options. On your side your education profile, expected grades personal statement and references are uploaded and they sort of match somewhere in the middle and you are made either a conditional offer or an unconditional offer.