system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: How is a degree from a place like Harvard or Yale any different from a degree in the same subject from somewhere else?

Also, is it any different in the UK with universities like Oxford and Cambridge compared to lower ranked uni's?
gpt
For starters, many of these places have good reputations because they have cutting edge research and the best academics who are at the forefront of their respective fields. It should be noted that this doesn't always translate to the best *teaching*, but that might well be beside the point.

Some economic theories of the value of education are that it is a signalling mechanism - that by getting a degree you can prove your competency/commitment to a potential employer (as opposed to actually making you a more valuable employee). With that in mind, a degree from a prestigious university indicates that you achieved their stringent entry requirements and put in the required work. 

EDIT: people pointing out the importance of making good connections - definitely should not be underestimated.  But the fact is that this is both a cause and an effect of the University's prestigious status.  They feed into each other.