A flight segment is a portion of a flight from one point to another. It is made up of four parts: a STEP, a LEG, a RISER, and a STAIR. A STEP is a single movement in a particular direction, such as the takeoff or landing of an aircraft. A LEG is a section of a flight between two points, such as from one airport to another. A RISER is a vertical part of a staircase, such as the steps between two floors. Finally, a STAIR is a set of steps that lead from one level to another, such as from the ground to the first floor of a building. Together, these four components make up a flight segment.