Convert otb to fb2

What is the difference between .otb and .fb2?

Description: The OTB (Nokia Over The Air Bitmap Image) file format is a type of image file developed for use on Nokia mobile devices. These files are specifically optimized for efficient transmission and display on Nokia phones, particularly older models. The OTB format is designed to be compact to facilitate over-the-air (OTA) transmission, which was an essential feature in the era of limited bandwidth and data transfer capabilities. The format supports monochrome graphics, making it suitable for simple images like icons and logos.; The FB2 (FictionBook 2.0 File) format is an open XML-based ebook format specifically designed for fictional literature, although it can also accommodate non-fiction. Unlike other ebook formats, FB2 focuses on the structure and content of the book, rather than its appearance. This means that the layout, font, and styling are determined by the e-reader device or software, offering a more uniform reading experience across different platforms.