MOBI is an ebook format used primarily by Amazon Kindle devices. It’s based on the open standard for digital publishing and allows for content reflow and support for images, links, and embedded fonts. MOBI files are widely used for ebook distribution and are compatible with various reading apps.
OEB is an ebook format used by the Open eBook standard for digital publications. It supports rich text, images, and hyperlinks, and is commonly used for distributing digital books and content. OEB files are now considered obsolete, replaced by the more widely used EPUB format.