Ogg is an open-source file format for multimedia. It can contain music, video, text, and metadata, and is optimized for streaming content. Because it is Copyright-free, Ogg is available for anyone to use in their software or media projects free of charge. Ogg is developed by the Xiph.org foundation.
While at 192kbps the encoding for OGG Vorbis is better than MP3 but at 128kbps both have the similar quality. Sound quality of OGG Vorbis is superior to MP3. Size of the file compressed in OGG Vorbis format is smaller than the size of same file compressed in MP3 format.