How to realize railway dispatching?

There is a proper term on the railway called block section. When we take the train, we can see a signal light every once in a while. There is a blocking interval between the two signals. Only one train is allowed to run in each section at a time, and other trains are not allowed to enter the section. This can ensure that the train will not rear-end. When a train passes a signal, the train-locomotive joint control installed on the locomotive will send a signal to tell the dispatcher that "a car has entered a certain section", so that the dispatcher can give the signal of the next section according to the running speed and passing authority of the car and direct the train to run. Similarly, why are there so many small stations (the domestic regulation is to set one at 10 km)? As Wei Zi Shen Xing said, space is needed to avoid it. At present, most trunk lines in China have been fully automatic blocked, which can realize continuous tracking and departure, and 3 ~ 4 trains can run at the same time in an interval, which greatly increases the traffic density and improves the line efficiency. However, in some places, trunk lines and branch lines are still semi-automatic or manually blocked, so that only one train can run in an interval.