The term "terminal" in an airport context is derived from the Latin word terminus, which means "boundary," "end," or "limit." Historically, this name was adopted from the railroad industry, where a "railway terminal" was the building at the end of the line where passengers either began or finished their journey. In aviation, the terminal serves the same structural purpose: it is the final point of land-based travel and the starting point for air travel. It acts as the interface where the two "ends" of the transportation systems meet. Interestingly, the first airport buildings weren't always called terminals; they were often referred to as "station houses" or "depots," but as airports grew into complex hubs where various transit lines converged and "terminated," the word terminal became the global standard for the buildings housing check-in, security, and gates.