A brief look at UK Education
Over the last few weeks I've noticed just how different the UK educational system is from the American one.
Apart from being an ex-consumer (and paying attention to the news) I'm not an expert but I'll try to describe how it works:
Most schools in Britain are supported by the state. It should be noted that one cause of confusion to people not from the UK is that a "public" school means a private school. They're called "public" schools because private schools were originally charities (legally, most still are). Only the rich send their children to private schools -- most people (including middle class parents) would send their children to state schools.
There are two basic forms to the state sector:
Primary/Secondary: Primary: 5-11, Secondary 11-16/18
Lower/Middle/Upper: Lower 5-8, Middle 8-13, Upper 13-16/18
The year you are in is solely based on your date of birth and it's which side of 1st September your birthday is on.
It used to be the case that school was compulsory until 16 but the last Government talked about making school compulsory until 18. I'm not sure if that was implemented.
GCSE (General Certificate of Secondary Education): Normally taken at 16 but can be taken any time since. This is normally 8-12 subjects and employers normally expect 5+ passes. Grades are A-G (A is good, G is bad) and a pass is considered to be C or higher. Most schools take 2 acedemic years to teach GCSEs.
After the learner has passed their GCSEs they have choose whether they want to study vocational qualifications, acedemic qualifications or a mixture of both.
There are literally 1000s of vocational qualifications and 99% of them would not help a person who wanted to go on to study a degree.
The main acedemic qualification is the A-Level and AS-Level. The AS-Level is half an A-Level. it's meant to have the same acedemic rigour but only half the topics are covered. People generally study 2-4 A-Levels (taking two years). Passing grades are from A-F.
If the learner wishes to go on to unverisity/college of higher education the normal route is to apply whilst they are studying for their A/AS-Levels. However, a person can apply to study any time thereafter (whilst a learner is studying their A-Levels is the earliest they can apply). They will apply through UCAS. On the form they will list all the courses and institutions they are interested in (there is a limited number allowed) -- e.g. Engineering at University of Bristol, Mechanical Engineering at De Montford University and Engineering at De Montford University would count as 3 choices. However, a learner can apply for fewer courses/instituations if they wish.
Most universities would then interview the students they feel would be a good fit there (from my understanding of the different systems, what student does in their private life, e.g. hobbies, is, compared to the US system, more important in the UK -- British universities tend to prefer people who are "well rounded").
After the interview the institution, if they are still intersted in that student they will make an offer. This offer may be conditional (e.g. "if you want to come here we'll accept you if you get 2 Bs and a C"). If the student impresses their interview and/or they already have passed their A-Levels they may get an unconditional offer (i.e. the institution will accept that student without any further conditons).
Once the learner has received all the offers they then have to choose a "firm" offer and, if they wish, an insurance offer. If the learner achieves the grades necessary to get into their firm offer then they will be starting at that institution at the time they said they would (on the UCAS form there's an option to say that a student wishes to take a year out). If the student doesn't achieve the grades for their firm offer (and if the people running the course listed in the firm offer are not willing to revise their offer) but achieves the grades for the insurance offer they will go on their insurance choice.
If a student grades are poorer than their insurance offer then either of the institutions they've listed as firm or insurance may offer them a different course. If there is nothing suitable from the institutions that the student expressed a preference in then there's the "Clearing System" where institutions with undersubscribed courses are matched with students who now have nowhere to go.
A-Level grades for everybody are publicly available.
Each university is different in the way it assesses and examines its students. However, the final grades are common:
1st -- best
2.i (pronounced "two one")
2.ii (pronounced "two two")
 If you're exceptional bright you could get an "A*".
 C or higher is considered a "Level 2" qualification and D is a "Level 1" qualification.
 I'm not going to use the word "student" because the word "student" only refers to those who are in education voluntarily and, given the last Government's proposal, I'm not sure if that applies any more.
 Again there is also an "A*" grade.
 See Wikipedia for an expansion of the acronym and the history of UCAS.
 I'm not sure if those universities run those courses as it's only given as an example of how UCAS works.
 If, after all the others have been made, the administrators feel that the course is undersubscribed they may revise their offer downwards. After all, the interview day is a two way process and it's a chance for the potential student to decide if they wish to go to that place and/or on that course. There are usually campus tours and other events when a student goes for interview.