When I was 9 years old I started a collection of US coins entirely out of circulation (you could get 50c Walkers, Mercury dimes, and Liberty Standing quarters at face in pocket change then), but by the time I finished middle school I had traded it all for early US Postage stamps. Never looked back and so I never learned to navigate the Sheldon grading system which had not been adopted by the expert services yet. So how does AU50 compare to VF VF+ EF and all that?
In theory, MS-60 has all of the luster still intact in the fields. 58 has rub in the fields. 55 has noticeable disappearance of luster from the middle of the fields. 50 has just a little bit of luster hugging around the devices. EF/XF might have tiny traces of luster, but for the most part, they don’t have any luster. The details are still pretty much full and sharp. VF starts having obvious wear to all the devices so that much of the fine details have worn away.