This tool is used to convert Web Media (webm) to Media Player 4 (mp4).

WebM is an audiovisual media file format. It is primarily intended to offer a royalty-free alternative to use in the HTML5 video and the HTML5 audio elements. It has a sister project WebP for images.

MP4 is a digital multimedia container format most commonly used to store video and audio, but can also be used to store other data such as subtitles and still images.