AZW3 format was created by AMAZON Company and came as a replacement to former AZW format. In the new AZW3 (KF8 or Kindle format) support for CSS3 and HTML is implemented and new parameters for formatting is used. All the new books of Amazon are available in format AZW3.
AZW3 (KF8 or Kindle format) – is an updated format from Amazon organization, using their DRM pattern and Palm database. Kindle devices of fourth generation and Kindle fire devices are supported. KF8- is a modified form of EPUB with internal decoding of mobi_unpack. At the beginning KF8 usually consists of MOBI file, which later on proceeds to – New version of EPUB.