You drive a pre-determined route, and an examiner watches you to see that you indicate, steer, position, and corner correctly. The emergency stop is done by an examiner stepping out in front of you.
I think it is different in varous test centres. I did the set route and standing beside the road thing, but that was in the 1960s. I've seen the local test people here in Newcastle use the follow on bike style tests, but nearby Durham seems to still use the old method.