One of the really incredible features of Mathematica is the access it provides to a number of large data sets. These data sets are stored and regularly updated by Wolfram Research and available over the internet. Simple Mathematica functions are provided that can be used to explore and analyze the data. If you take a look at "guide/DataCollections" in the Help Files you'll see that included among the data sets are mathematical data (polyhedra, graphs, knots, and the like), physical and chemical data (elements, chemicals, isotopes, particles, and the like), country and city data, financial data (currency, stocks, and the like), and word data (dictionary, thesaurus, and the like). Using these data sets you can easily render a three-dimensional plot of your favorite molecule, chart the closing share prices of the stocks in your retirement portfolio, or build star charts for the night sky at your location on earth.

In this chapter, we'll explore two of these data sets: CountryData and WordData. When working with large data sets of any kind the necessary tasks are usually the same. We need to import data from some source, select features of the data that interest us, analyze the data, and usually display the data and our analysis in some way (graphical, tabular, and so on), often so that we can present our findings to others.