VOD (video on demand) is a catalog of pre-recorded titles a viewer can start at any moment. Because the content already exists as files, the platform encodes each title once, stores the renditions, and serves them on request — there is no deadline and no "second chance" the way there is with live. That makes the VOD pipeline the more forgiving of the two: encoding can take its time, use multiple passes, and apply per-title optimization to squeeze quality out of every bit.
VOD is a delivery mode, not a business model. The same on-demand catalog can be monetized as SVOD (subscription), AVOD (ads), or TVOD (rent/buy), or any hybrid. What unites all of them is the request-driven flow: the viewer picks a title, the player fetches the manifest, and adaptive bitrate streaming takes over.
Architecturally, VOD emphasizes catalog management, metadata, search and recommendations, and long-tail storage economics, since a large library is mostly cold content punctuated by a few hot hits.
