Gateways and hubs are locations where flows converge and are the foremost expression of global connectivity. However, they differ in terms of the nature of their connectivity. While a hub is a central location in a transport system with many inbound and outbound connections of the same mode, a gateway commonly implies a shift from one mode to another (such as maritime / land). A gateway performs an intermodal function (between modes), while a hub is mostly transmodal (within a mode) in nature.
The meaning of gateways and hubs can vary according to the transport mode, with each mode having its technical characteristics, economies of scale, and commercial relations. Transport corridors are commonly linking gateways to their hinterland. Gateways tend to have temporal stability as they commonly emerge at the convergence of inland transport systems and through the long-term accumulation of infrastructure and investments.
The importance of a hub can change depending on the commercial strategies of its users. For instance, a transport company (e.g. maritime shipping or air carrier) may switch from one hub to another if it improves its operations or commercial opportunities. Flows, origins, destinations, and the modes used can therefore change. In this context, a hub can lose a share of its connectivity as the network it is part of is reorganized. The functions of gateway or hub are not mutually exclusive since a location can assume both functions if it fits the commercial strategies of carriers.
The functions of centrality and intermediacy are particularly relevant to the emergence of a global nodal space since centrality focuses on nodes as the origin or destination of flows. In contrast, intermediacy focuses on nodes as intermediate locations where transshipment is performed. While central locations correspond to large metropolitan areas, intermediate locations have developed unique geography where the importance of a location is more derived from its relative accessibility (in terms of other locations) than its intrinsic characteristics.