Before you go to the check-in you need to have your luggage screened, to make sure you don't have anything dangerous in it.

At the check-in counter you hand in your passport and your ticket, to be checked.

Then your luggage is checked in, and all you keep with you is your passport, your boarding pass, and a small bag to take on the plane with you.

If people want to wave goodbye, they sometimes stand inside, and sometimes go out to the viewing platform, to see the plane leave.