Convert xhtm to art

What is the difference between .xhtm and .art?

Description: The Extensible Hypertext Markup Language (XHTML) file type is an XML-based markup language for creating web pages. It is a hybrid of HTML and XML and is designed to replace HTML as the main language for creating web content. XHTML files provide a more flexible, extensible structure for web documents, allowing for more complex page designs and better integration with other web technologies.; PFS Art Publisher Image (ART) is a raster graphics file format used for storing digital images. It was developed by Progressive Networks for use in their Progressive FreeStyle Art Publisher software. ART files are compressed using the run-length encoding (RLE) algorithm, which allows them to store large images in a relatively small file size. The ART format supports up to 24-bit color and is often used for storing digital photos and other images.