Do you wait in line or online?

If there is an actual physical line on the floor, and you are on it, then you are on line. If you are in a line of people, you are in line. If you are in a line of people, and also standing on a physical line on the floor, then you are both in and on line. If there is a group of people, standing in a line, and you are standing on top of the group of people standing in line, then you are standing on line.