azw3 The American company Amazon is a recognized powerhouse when it comes to all things related to books. Their proprietary eBook readers dubbed the Kindle which was first released in 2007 is a testament to this. The .azw file format is the filename extension associated with eBooks designed to be read on Amazon's proprietary Kindle device and through their free but closed source Kindle software for smartphones, PCs, and Macs. The format is incompatible with any device other than kindle and its associated software. In order to open files saved in this format on non-kindle devices, one would have to convert the file to another format such as the open ePub format or PDF. Some converters can also convert other formats into .azw files which can later be opened on a kindle device or application.
zip The .ZIP file extension format is a file archive and data compression format originally developed and released in 1989 by Phil Katz. With compatible zip format software, a file or a group of files can be packed (compressed) into a single .zip archive which can later be unpacked (decompressed). The zip file archive format facilitates the distribution of multiple files as single archives particularly over the internet and networked systems. Many operating systems have native support for the file format and can usually open zip archives without the need for third party software. Microsoft windows for instance has had native support for the ZIP format since Microsoft Windows 98, similarly Apple's Mac OS includes ZIP support through its default archive file handle Archive Utility.