How are urban and suburban areas alike?

I have been trying and trying to find this answer so PLEASE someone, tell me what it IS!!! PLEASE!!! !!!

urban areas wouldn't have a lawn just as an example.. the closer to the capital the more urban as you move outward into places where neighborhoods with spaced out houses would be the suburbs (suburban area) and you move more outward into the rural area (out in the country ) wether it be mountains or farmland or nothingness

another way to determin, would be population density (people per square mile)