MTR is the name of the Hong Kong subway. What's the difference between Hongkong subway and Chinese mainland subway?

MTR is the name of the Hong Kong subway. The difference between the Hong Kong subway and the Chinese mainland subway is that there is usually a line opposite the platform of the Hong Kong subway, because most people who get off the train change instead of sitting back in the opposite direction. The platform of the mainland subway is opposite to the same line, that is, the nearest transfer distance is given to those who have passed the station, but not to those who transfer. If you want to change, you need to climb the stairs.