Inflation changes the value of our money. For example, $1000 in 1980 would require $2,790 today in order to purchase the same amount of goods and services. Fortunately average wages have gone up since 1980 as well. When ESPlanner asks for inputs, it typically gives you an option to input values in "real" dollars (inflation adjusted or also called "today's dollars") or in "nominal" dollars (not inflation adjusted). The program also allows you to set your assumption about inflation in the future.