.FB2 (FictionBook) - is a single file format XML. The images in the book (format PNG and JPEG) are integrated directly in XML, using the coding algorithm Base64. FictionBook typically compressed using ZIP-archiver (in this case, a format .fb2.zip or .fbz).
If you need to convert the e-book or word document format FB2 (FictionBook) you can use our online converter in FB2. To convert you just select your text file and click "Convert file".