Entry Requirements for UK universities

Hi guys, I will be applying to UK Universities from this September. I have been looking at the grade requirements for the unis I want to apply to. When I apply for uni like the university of Glasgow, their entry requirements on the website for computer science are like AAB-ABB. so if they make me an offer to me lets say conditional, will the grades be the ones stated on the website or can they lower it to like BBB? i am still bit confused.
Also, do UK universities still give unconditional offers to students?
thanks.

They can change the offer to a lower one but its quite rare, but maybe not as rare considering the circumstances this year.
They do still give out unconditional offers although for a top tier university this again is quite rare.