<p>Which country are you from?
If you’re from places like Hong Kong and Singapore, you can apply directly with your HKAL or Singapore A-Level grades.</p>
<p>The British university system is quite different from the US one.
British students will have had a supposedly more advanced preparation in high school (they call it sixth form) by taking A-Levels so they can graduate from universities in only three years.
So when British universities consider international students for admissions, they look for evidence of this kind of advanced preparation.
The most widely recognized international qualification is the International Baccalaureate Diploma (some British high schools actually offer this system instead of the traditional A-Level).
AP stands for Advanced Placement, and is an American system that allows high school students to bypass certain introductory courses and gain credit in universities.</p>
<p>BTW, if you’re international and doesn’t have appropriate English language qualifications (i.e. GCSE, IB…etc), you should take IELTS before applying to British schools.
TOEFL should be accepted, but I’ve heard they prefer IELTS.</p>