Most of our datasets deal with long-term global trends. For example, “Infant Mortality Rate per 1,000 Live Births” covers the period between 1960 and 2015 in almost 200 countries. We call these datasets Dynamic D in the sense that they allow the users to interact with the data in a multitude of ways (e.g., to choose from a variety of visualizations, to pick different countries and regions, to select specific time periods, and so on).

However, some datasets are less comprehensive (e.g., the price of U.S. airline tickets). These Static S datasets are still useful in documenting human progress, but they do not allow for much user interactivity.