And what is that data journalism?

The data journalism (or data journalism, in English) is a journalistic practice that seeks to harness the enormous amount of data available in a multitude of sources, preferably digital (and the web is the first, but not the only) to tell news stories. Many of these data and the relationships established between them, can explain increasingly complex phenomena in a relatively simple manner. Even more ideally, allow sharing not only their own news or reports obtained through them, but also help recipients can review the data themselves and draw further conclusions.
In Castilian, yet there are too many examples of this phenomenon, which is slowly growing. Maybe it's better to lead by examples such as The indultómetro, The Heritage of Spanish MPs or as big, analysis on subsidies to companies owned bus lines in Argentina (in this country, buses are called groups, as it is not clear).
A whole wealth of information (and pun intended). What has not been clear to you yet? If so, you can look on the Data Journalism Hangout (a speech broadcast live through Youtube) in which three journalists recognized in this field you explain it in a pleasant way, and while he says. The journalists are Sandra Crucianelli, of Argentina; Mar Cabra, Spain, and Olga Lucía Lozano, Colombia.
Some of the data practices of journalism are not exactly unknown to her documentary. Could they be a source of expertise that is not future, but already present?