Before anything, let us first talk about what ePUB actually is. In the world of dynamic digital publishing, ePUB is basically a format which is supported by the Book Industry Study and has been developed and maintained by International Digital Publishing Forum (IDPF). As an open-source format, it has evolved over a period of time, that too with the changing technologies. Being a dynamic format, ePUB is well supported by HTML5 and CSS3 technologies allowing you to hyperlink content with internal as well as external references. Believe it or not, it is SEO-friendly which makes the content scannable on different browsers based on the keywords incorporated. The latest version is ePUB3.