What does connecting train mean?

A special means of transportation.

Connecting trains are a convenient transportation method for passengers, mainly used to connect two different train stations or airports. When passengers need to go from one train station or airport to another, they can choose to take the connecting train, avoiding the trouble of changing trains or taking public transport. Special connecting trains usually enter the station first to ensure that passengers complete the transfer within the specified time. A shuttle bus generally refers to a vehicle used to travel between two fixed locations for a specific short distance. Shuttle buses are generally used in several places: Airports, also known as shuttle buses, are vehicles that connect the airport terminal to aircraft at remote stands. Hotels, vehicles connecting the hotel to the nearest bus station or transportation hub. A hub station connects two hub stations, such as a subway and a train station, or a subway and an airport terminal.