eBooks are produced in many formats, each with their own pros and cons. The two most popular formats are EPUB and PDF.
EPUB: EPUB is an open standard developed by the IDPF, with significant input from Adobe. Simply put, EPUB is a way of delivering styled, reflowable content to eBook readers. In the format wars of eBooks, EPUB is fast emerging as the winner. The text in an EPUB eBook can reflow to suit the reading device or reading software (for example, to suit screen size or a user's own preferences), but still allows a designer to specify a range of aesthetic and navigational features, including fonts, a clickable table of contents, and embedded sound and video.
PDF: PDF (Portable Document Format) remains one of the most useful and common file formats for documents in the world. It was the first reliable format to enable people with very different computers to look at the same file and see the same thing. Most people use it for sending each other documents that mustn't change from one computer to another, like contracts or logos. PDFs can include a surprising number of special features, including hyperlinks, embedded sound and video, and interactive forms.
