What is "ogg"
Ogg is a free encapsulation multimedia format or container file oriented to stream which is widely used on the internet through live radios and video uploads in which you do not need to have all the video downloaded to start watching it.
In other words, it can be read and written in the same step, without having to store all or much of the data stream before. This feature is a natural requirement for streaming and pipeline processing.
For more information, visit: Ogg.