What does it mean that this plan needs to transfer at Guangzhou East-Guangzhou South?

This plan needs to transfer at Guangzhou East-Guangzhou South, that is to say, first arrive at guangzhou east railway station, then go from guangzhou east railway station to Guangzhou South Station, and make the second trip at Guangzhou South Station to reach the destination. Transfer is a technical term and life vocabulary in the field of transportation, which refers to one or more railway stations for passengers to take trains between different lines without leaving the station payment area and purchasing tickets separately. The concept of transfer is common in urban rail transit, but it is also applicable to other railway transportation, road transportation, air transportation and water transportation.