Depending upon how you may phrase a query, Google will sometimes jump into a Q&A (question and answer) mode. This is described on one of Google’s help pages:
Want to know the population of Japan? What currency is used in Algeria? The birthplace of Bono? Hit us with a fact-based question or query (like “population of Japan”) by typing it into the Google search box. We’ll search the web and display the answer at the top of your search results page. We also link to our source for this information so that you can learn even more.
The same feature is available through a moble phone service from Google, a little more straightforward in that you know you are only in Q&A mode when asking a question: