I remember when I had a lesson about OSI layers, where the teacher has carefully described all the layers in detail
and then said something like "most of this is not important, these layers don't really exist, TCP/IP got popular first because it's just much simpler than OSI was"
and then said something like "most of this is not important, these layers don't really exist, TCP/IP got popular first because it's just much simpler than OSI was"