“Prospective international students can get a second chance at U.K. university admission through a process called Clearing.” …
The top UK universities don’t use clearing. Admission to UK schools is based on academic achievement and it stands to reason that the most academically gifted and highly motivated candidates don’t miss their conditional offers in sufficient numbers that the top schools need clearing to fill their classes. Clearing is typically for candidates who miss their required grades for their first choice and have to shop down for a place at a lower tier school. You may see Russell group schools advertise occasionally for adjustment candidates, those candidates who greatly exceed their expected A level results pushing them into higher tier of university placement, but the tippy top universities dont use clearing and adjustment may be literally a handful of candidates…
Actually clearing is for students who miss their condition by a lot (if predicted AAB they get BBB) because some universities will “work” with the candidate depending on the situation for an A*BB for instance. And students have a second choice, an “insurance” choice that they like less than their “firm” or first choice AND requires lower conditions.
BUT… for Americans it can just mean “more openings if you don’t like your current US options”.