What is meant by the term …

Arithmetic density, also known as real density, is very simply the total number of people divided by the total land area. Physiological density is the number of people per unit area of arable land. Arable describes land that is suitable for growing crops.  The main factors determining population distribution are : climate, landforms, topography, soil, energy and mineral resources, accessibility like distance from sea coast, natural harbours, navigable rivers or canals, cultural factors, political boundaries, controls on migration and trade, government policies, types of economic activities, technology including type of farming and transportation facilities, social
organization and but not the least, demographic factors like changes in natural increase and migration.