The ePub, Mobi, and ePDF formats can include embedded meta data (information about the book) for e-readers and search engines. This data is often displayed in the e-reader device allowing readers to know what a book is about before they select it.
Meta data categories
The meta data doesn’t happen on its own. It must be put there. Ebook conversion software doesn’t add it. Only a knowledgeable designer or producer of the ebook file will know to enter the information. The data is collected from whatever sources are available—usually the information on the publisher page and the book’s backcover. The main meta data categories are as follows: