Human population:

Human population refers to the number of people living in a particular area, from a village to the world as a whole. A secondary meaning of population is the inhabitants themselves, but in most uses population means numbers. The overwhelming bulk of human population growth has occurred since the Industrial Revolution began, more than half since 1950. All but a small percentage of the roughly 80 million people added to world population each year live in the world's developing countries, which are home to 80 percent of humanity and more than 95 percent of world population growth. In Europe and Japan, small average family size and relatively modest immigration levels are leading to a leveling of, and even decreases in, population. In the United States, Canada, and Australia, slightly larger families and higher levels of immigration make for continued population growth.

World population grows because births significantly outpace deaths on average. This imbalance occurs not because women are having more children than they once did—quite the reverse—but because improved sanitation and health mean that many more children than in the past survive to become parents themselves.