Flight Check-In is the process that passengers complete before boarding an airplane. It typically involves confirming your reservation, selecting or confirming your seat, and obtaining your boarding pass. Check-in can be done online, at a self-service kiosk, or at the airline's check-in counter at the airport. During check-in, passengers may also need to check in their luggage, which involves tagging the bags and handing them over to the airline staff. It's important to arrive early to allow enough time for check-in, security screening, and boarding, ensuring a smooth travel experience.