jet bridge vs footbridge

jet bridge and footbridge both are nouns.

Word	Noun	Adjective	Verb	Adverb
jet bridge	Yes	No	No	No
footbridge	Yes	No	No	No

As nouns, footbridge is a hypernym of jet bridge; that is, footbridge is a word with a broader meaning than jet bridge:

jet bridge: an extendible bridge for loading passengers onto large commercial airplanes; provides protected access to the plane from the gate
footbridge: a bridge designed for pedestrians

Other hypernyms of jet bridge include overcrossing, pedestrian bridge.

jet bridge (noun)	footbridge (noun)
an extendible bridge for loading passengers onto large commercial airplanes; provides protected access to the plane from the gate	a bridge designed for pedestrians