Which part of the dictionary definitions don't you understand?
OneLook: General dictionary sites
Interested in Language
What's the difference between Ettiquette and Custom?
noun /ˈet.ɪ.ket//ˈet ̬.ɪ.kət/ [U]
the set of rules or customs which control accepted behaviour in particular social groups or social situations
It is a bit confusing for me since etiquette overlaps with custom!