An origin server is the source from which a delivery system obtains a resource, such as a playlist or media file. A CDN or proxy may serve a copy to the viewer instead of exposing the origin directly. Origin availability, capacity and configuration can therefore affect users even when intermediary servers are healthy.
A practical example
An edge server may deliver cached film segments successfully while a newly requested playlist needs an origin response. If the origin fails, some already-cached content can remain available while fresh resources stop loading for viewers.
A common misunderstanding
A functioning homepage or cached image does not prove that the media origin is healthy. Test the failing resource and time period rather than assuming every server shares one status.
Related terms
Stable technical definition. Editorial approach