The best book about Bitcoin

Now that bitcoin is bumping up against $16k, a few people have asked me how they can learn more about bitcoin. I've read about 10 books on Bitcoin (for my work as a researcher at Institute for the Future) and my favorite one is Bitcoin for the Befuddled. It does a great job of explaining how Bitcoin works, going into detail without being overly complex. It's several years old, but the basic principles of bitcoin's blockchain haven't changed.