<p>The term “college” has many meanings in the UK. Some of them are high schools. Some are universities or parts thereof and can award degrees. There is no fixed meaning other than educational institution.</p>
<p>I never said I was an expert on access courses, but I don’t think you can generalise them all as an isolating experience. I know someone who did one at Bath Spa uni and had accommodation and all. Just trying to think of alternative options to help the OP as in the limited information they have given I do not see the clear evidence of academic ability in computer science that they need for Oxbridge admission.</p>