* EPUB: This is the most common e-book format, and it's compatible with most e-readers and tablets.
* PDF: This is a universal format that can be viewed on any computer.
* MOBI: This format is specifically designed for Amazon Kindle devices.
* HTML: This format is used for web pages, and it can be viewed in any web browser.
In addition to these formats, VitalSource also offers a proprietary format called Bookshelf. This format is optimized for the VitalSource Bookshelf app, which provides features such as annotation, highlighting, and search.
The specific format of a VitalSource e-book will depend on the publisher. Some publishers may only offer their books in a single format, while others may offer multiple formats. You can usually find the available formats listed on the VitalSource website or in the Bookshelf app.