Old Beijingers say haircut and shaved head, in the end what is the difference between

Not much of a standard, there are all kinds of sayings, some old people say, haircutting and shaving, pushing the head is the same, shaving the head is the past with a knife shaving the head of the said passed down, pushing the head is later on there is a barber pusher after the said, there are old people say, shaving the head has to be a bald head of the time to say so, I do not know which is right

.