Convert xhtml to otb

What is the difference between .xhtml and .otb?

Name: Extensible Hypertext Markup Language File; Nokia Over The Air Bitmap Image

Description: XHTML files are a type of markup language document used to create webpages. It is an XML-based version of HTML and is designed to meet the needs of Web developers. XHTML files have a .xhtml extension and can be viewed in any web browser.; 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.