A manifest is the index file that tells the player what a stream contains and where to fetch it. In HLS it is an M3U8 playlist; in DASH it is an XML Media Presentation Description (MPD). The manifest lists the available renditions, their bitrates, resolutions, and codecs, the audio and subtitle tracks, and the locations of the media segments along a timeline.
The manifest is the entry point to playback: the player downloads it first, parses the ladder, and uses it to drive adaptive bitrate logic — requesting segments from whichever rendition best fits current throughput. For VOD the manifest is static and lists the whole timeline; for live it is a moving window that the player re-fetches periodically as new segments appear and old ones age out.
Manifests also carry the metadata that makes advanced features work: DRM signaling, ad-insertion markers, multiple audio/subtitle options, and timing information for low-latency modes. A malformed manifest is one of the most common causes of playback failure.
