What type of city is considered an "offline station" for airlines?

An "offline station" refers to a city or location where scheduled airline services do not exist. This means that airlines do not operate regular flights to or from that city. Typically, these offline stations may not have the passenger demand or logistical considerations that would justify regular service. Consequently, they may only have occasional flights or may serve as a point for special charters or other infrequent operations.

In contrast, cities with frequent flights, those used for long-haul flights, and major hubs for connecting flights all typically have established and consistent airline services. These types of locations are crucial to airline networks, providing regular transportation options for passengers traveling over various distances or needing to connect through larger airports.