The hub hospital is a larger institution, such as a comprehensive stroke center or a tertiary care facility, that provides physician call coverage service for remote consultation with facilities that require such coverage. 

Typically, patients are transferred to the hub hospital for downstream care, if recommended by the physician after a remote consultation.

The spoke hospital is an institution that does not have specialists covering their emergency room and require remote consultation for acute medical conditions.

The consulting physician is typically, but not always, affiliated with the hub hospital and provides call coverage services to spoke hospital emergency rooms.