Birth rate is a branch of demography that determines the number of live births per thousand inhabitants of a given area or region over a given period of time, usually one year. The calculation is made by dividing the number of live births by the total population of the region.
Demographic density is an index also known as population density or relative population. Refers to the distribution of inhabitants in a given area, it is the average resulting from the division between the total number of inhabitants and the occupied area.