AZW, an earlier version of AZW 3 (also known as Kindle Format 8), is an ebook file format that was first introduced on Kindle devices in 2007. It is based on the MOBI file format, which Amazon acquired in 2005. Despite being based on MOBI, AZW files have better compression than MOBI files and can be used on Amazon Kindles or any device with Kindle software.

.txt (Text File) The .txt file format is a standard text document format that contains unformatted text. It is universally recognized by virtually every text editor and word processing program. TXT files are useful for storing information in plain text with no special formatting beyond basic fonts and font styles. This format is widely used for its compatibility and simplicity, as it can be opened on almost any computer platform.