The AZW and AZW3 extensions are the proprietary eBook formats from Amazon. Although it’s never been officially confirmed, AZW and AZW3 format are similar to the MOBI format also known as Mobipocket, Developed by a French company in the year 2000 and later acquired by Amazon in 2005. AZW is the first version, and was released in 2007 along with the first Kindle.
The AZW, AZW3, KFX are the eBook format for Kindle. This File Format is created by Amazon.com and this format is specifically for Kindle only
