In a Nutshell: 航班 (hángbān) is the word you see on your ticket and on the departure board at the airport. It doesn't mean “airplane” (that's
飞机 fēijī). Instead, it refers to the scheduled service itself—the specific, numbered, and timed journey you book. Think of it like a bus route number, but for a plane. If your friend asks “What flight are you on?”, they are asking for your
航班.