HTML (Hypertext Markup Language) is the standard markup language used for creating web pages and web applications. It describes the structure of a web page semantically and originally included cues for the appearance of the document. HTML provides the basic building blocks for webpages, allowing for the integration of text, images, multimedia, and other elements. HTML files are essential for the World Wide Web and are interpreted by web browsers to display content.

.azw (Amazon KF8 eBook File)
The .azw format is an eBook file format developed by Amazon for use with their Kindle e-readers. It's also known as Kindle Format 8 (KF8), and it supersedes the older AZW format.
AZW supports a variety of features including text reflow, images, tables, and interactive elements. It is designed for a more enriched reading experience with support for HTML and CSS content.
AZW files are typically used for eBooks with complex layouts, such as textbooks, comics, and children's books.