a discussion on the importance of osu beatmapping concepts in response to / request_for_mappers_of_this_sub
this is more aimed towards newer mappers who don't really know how to structure their maps. older mappers know about this stuff already, but it's not explained in any easy-to-find places
the main map: https://osu.ppy.sh/s/487559
the map at the end: https://osu.ppy.sh/b/990949