i dont know much about modding and would like to know a simple question

do i need to download this to play other levels that use these assets or do the ppl who make the maps just need to download these asset packs?

i see a lot of ppl are starting to use these in there mods and was wondering, do i also need them installed for those levels made by others to not end up with purple and black checker boards on all the items or those red ERROR entity's you get when your missing the files

and if anyone can tell me if there not needed and i download/subscribe to say 5 different levels in the workshop that uses these assets am i downloading the same data every time or is it pooled in a location that any mod that uses them can have access to them

or will i have this stuff downloaded 5 times over for each level that uses them, i would rather just have them once on my hdd rather than the same files duplicated in 20 different places.