Convert webm to art

What is the difference between .webm and .art?

Description: A WEBM file is a compressed video saved in the WebM format, an open, high-quality video standard. It stores video compressed using VP8 technology and audio compressed using Ogg Vorbis compression. WEBM files are commonly used for delivering online videos using the HTML5 <video> tag.; 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.