The phrase "Free Books" refers to literature that is available for reading without any cost or charge. This could mean that the book is either in public domain, has been released under a Creative Commons license allowing free distribution, or it may be an excerpt from a larger work made available by the publisher or author as a promotional tool. In some cases, "free books" might also refer to digital versions of books that are offered for free through online platforms such as Project Gutenberg, Open Library, and other similar websites where users can read, download, and share e-books legally without any cost.