What are maria and highlands on the moon?

Actually "maria and highlands" is not the same meaning like on Earth. 

Maria (seas) and highlands (mountains) are irregular landscape of the moon surface. There is not water on moon because it has no atmosphere. 

Master planned communities outside of chicago. note: population density means people living in an area per square mile. chicago, an urban and highly populated area has a much more higher density than a desert, amish community, settlement, or nomadic region.

Answerepicenter;