.OGG File Extension Description:

The file extension .OGG is a standardized bitstream format and can be opened by multiple audio programs. It is designed primarily for audio streaming and audio manipulation. Under this file extension, Audio and video codices, which could be from independent sources can be multiplied and managed according to the user’s preference.

The same is possible for metadata featured in either the audio or video codices as would be the case with music or videos that have subtitles. Since the file extension .OGG is available in an open format, it is commonly used.

Learn more about .ogg files here: http://ogg.file-extension-library.com/