How would you explain to a dummie what is buzz marketing?

Im a little confused. Is buzz marketing paying a group of people to "test" your product and then make them "Talk to the world" about it, or is it simply the Opinions of people who bought the product and spreaded the word about it? Can somebody explain in very understandable words? thanks!

Buzz Marketing just refers to getting a bunch of people talking about it so everyone wants it before it’s released. Some hit movies use this very well.