The document discusses how world population has changed over time from 1 CE to projected estimates in 2300. Rather than showing population changes through traditional line graphs, it presents population density through a series of maps where country sizes are exaggerated based on population. The maps from different time periods like 1 CE, 1500, 1900, 1960, 2050 and 2300 demonstrate how human populations have expanded globally over the centuries and are projected to continue increasing substantially.