What are population processes?

World Population Day is on July 11th so we will spend the lead up to the day highlighting some basic concepts in the field of population. 

Today we start with population processes.

Population processes are the three factors that lead to changes in the size and composition of the population. These are fertility, mortality, and migration. 

The population is added to in the following ways:

• Fertility (births)
• Immigration (movement in)

The population is subtracted from in the following ways:

• Mortality (deaths)
• Emigration (movement out)