Describe regions where population is clustered and where it is sparse

regions where population is clustered are over-populated regions while regions where population is sparse are called under-populated

Explanation: the term clustered population indicates the number of people living in the region exceeds the available space which is one of the resources needed for survival making the population of the region over-populated.

The term sparse population indicates the number of people is very sparse and less than the available space which indicates severe under-population