E-books come in many different forms. Here are some common ones: 1. The e-book format: This is an e-book format introduced by Amazon for the Kindle device. This format has a good reading experience, can adapt to the screen size and support multiple languages. 2 MOBI-format: This is another common e-book format that was originally introduced by the company, iPhone. The MOBI-format can be read on different devices, including Kindles, e-readers, and other digital devices. 3. PDF-format: PDF-format is a widely used e-book format suitable for all types of devices, including computers, tablets, and smart phones. The PDF-format protected documents from damage and supported multiple reading modes. 4. TMT format: The TMT format is a simple text format that does not provide any images or styles. It is usually suitable for personal documents or small projects but not for large documents or documents that require a good reading experience. 5 EPUB format:EPUB format is an e-book format introduced by Amazon for Kindles and other digital devices. The EPUB format supports a variety of text and images and has a better reading experience.