Thais can stay for 24 hours inside the airport. Can you tell me what inside airport means

I am canadian and can leave the airport but the rules say my thai friend cannot.I want a hotel for 1 night. Google lists about 40 hotels that are listed as inside the Pudong airport in Shanghai. I do not understand as some are several kilomiters from terminal. Could you please tell me what defines inside airport or the name of some hotels inside.