The title is a bit misleading, as about half the book is dedicated to hostile and neutral worlds not belonging to the Federation.
Author Shane Johnson did his best to include as many alien races as he could from Star Trek: The Original Series, The Animated Series, the films, and The Next Generation. Though this was published early in TNG’s run (1989), even at that time it was nowhere near comprehensive (especially since TNG introduced at least one new species/world each episode).
Johnson had assistance from many people at the Star Trek production offices when he created this book. However, like so many Star Trek books, it is considered outside canon. There is even a disclaimer stating that “the facts and background details...as presented in (this book) are solely the author’s interpretation.”
