Two Standards, One Idea
Both HLS and DASH deliver video as small segments described by a manifest. The player reads the manifest, picks a rendition, and fetches segments over plain HTTP, which makes them cache friendly.
HLS
- Created by Apple and native on its devices
- Manifest is a playlist file listing variant streams and segments
- Historically used a transport stream container, now also fragmented MP4
- Widest device support especially on phones and tablets
DASH
- An open standard independent of any vendor
- Manifest is a description file listing adaptation sets and representations
- Codec agnostic, so it adapts as new codecs appear
- Not natively supported on some Apple devices
Choosing
Many platforms ship both, using a shared set of segments and two manifests. This maximizes device reach while reusing the same encoded files.
Key idea
HLS and DASH both stream segmented video described by a manifest over HTTP; HLS wins on Apple reach while DASH is an open codec agnostic standard, so platforms often serve both from shared segments.