Google uses an algorithm called PageRank to rank search results.
Why it is true
PageRank, developed by Larry Page and Sergey Brin in 1996, evaluates the importance of a web page based on the number and quality of links pointing to it. This algorithm revolutionised the way internet searches work.
Source: Nature
Would you rather be asked first?
This is the reading side of the site, so the answer is in the sentence above — that is the whole point of it. Test yourself works the other way round: the question comes on its own, and the fact and the explanation only appear once you have answered.