I know one of the uses -
if you're a teacher who works with a class with 27 pupils and a class with 18 pupils, and you want each class to have a sports tournament with the winning team from each class playing each other, you would want to know the largest possible team number that you could break both classes into. In this case, both classes can be split into teams with 9 players, as that's the HCF.

To split 2 sections
to equally distribute two or more sets on item
to figure out how may people we can invite
to arranfe something into rows an groups

i hope it'll help u pls mark as best
urs pixie