Quantity has a quality all its own, as the saying goes. That’s especially true of information. The more you’ve got, the more useful it becomes. Knowing sensitive facts about one person, or a dozen, may be trivially useful. But analyze the same facts about 100 million people, and you can cure diseases, win elections, or earn billions of dollars, because unpredictable insights emerge when you turn computers loose on vast storehouses of information.

There’s a nickname for the concept: “big data.” It’s one of the buzzwords of corporate executives, tech-savvy politicians, and worried civil libertarians. If you want to know what they’re all talking about, then “Big Data’’ is the book for you, a comprehensive and entertaining introduction to a very large topic.