i always read frontend/backend as an analogy to how e.g. a store has a front (for customers) and back (not for customers), or like how a stage has a back-stage.

i always read frontend/backend as an analogy to how e.g. a store has a front (for customers) and back (not for customers), or like how a stage has a back-stage. so the metaphor, and "semantic connection" would be that "back" means "the bits you don't see and don't directly interact with"