What does line 360 mean?

China has a famous saying-"360 lines, each line is the best". I don't know how many years this proverb has been circulating, but it is a household name, known to all women and children. The name of the line began in the Southern Song Dynasty. The so-called "360 lines" refers to all walks of life, that is, social posts. Including meat shop, seafood shop, fresh fish shop, restaurant, rice shop, sauce shop, palace powder shop, flower shop, tea shop, soup shop, medicine shop, clothing shop, silk shop, embroidery shop, needle and thread shop, leather shop, binding shop, firewood shop, coffin shop, old shop, autopsy shop and net shop. Tsui Hark, a Qing Dynasty man, said in "Clearing Banknotes": Thirty-six walkers have their own occupations. About its division of labor, it is 36 lines; Second, it is seventy-two lines; Ten is 360 lines.