If a book or a TV show is about science, and is made easy so everyone can understand, then it is popular science. It is popular because it is made for the whole population, not just for scientists. Nature documentaries are examples of popular science.
Popular science is non-fiction, so it is not the same as science fiction. Popular science is also not the same as Science journalism. Science journalism is what journalists write to report the newest theories and discoveries made in science, but popular science is not always about what is newest.
Some famous people who make popular science are David Attenborough, Isaac Asimov, Jacob Bronowski, Arthur C. Clarke, Martin Gardner, J.B.S. Haldane, Stephen Hawking, Bill Nye, and Carl Sagan.