Having lived in urban and suburban and even somewhat rural areas, I can name some differences.
Cities have more people in a smaller place. Buildings are closer together, so cars aren't usually very necessary because you can walk between places, and there is usually far more public transit than you'd find out in the suburbs or rural areas. Cities tend to have more cultural opportunities -- there are arenas for sports, theaters for plays, more museums, things like that. Not that they are all in the city, but you'll find fewer of them in suburban/rural areas.
Suburbs have larger homes (again, usually) farther apart. There is some public transit (for me, bus and regional rail), but not as much as in a city. Walking to do shopping or go out isn't practical. Not impossible, just not very practical in terms of carrying heavy bags, etc.
And if you go farther out to where it's rural, you'll find fewer people spaced farther apart, etc.
Written 20 Jan