What is "tonggeun"

The Tonggeun (previously called Tongil-ho) is a class of short-run commuter trains operated by Korail, the national railroad of South Korea. On timetables, the name is always translated as "Commuter." They typically operate once or twice daily in each direction, along a few tens of kilometers of track. They thus provide an important function for many smaller rural communities (and also some New Towns around Seoul), which often lack good public transit connections.