What is the difference between HLS and DASH?
HLS and DASH are the two dominant adaptive-bitrate streaming protocols. Both chop a video into short segments at several quality levels and let the player switch between them on the fly. HLS was created by Apple and is the only format iPhones and iPads play natively; MPEG-DASH is an open standard used widely elsewhere. Serving both covers every device.
What they share
Both are HTTP-based adaptive streaming. A source is transcoded into a ladder of renditions, each split into segments a few seconds long and described by a text manifest — an .m3u8 playlist for HLS, an .mpd file for DASH. The player reads the manifest, fetches segments, and steps up or down the ladder as bandwidth changes.
Where they differ
HLS is Apple's protocol and the only one Safari on iOS plays without a JavaScript player. DASH is codec-agnostic and an ISO standard, common on Android, smart TVs, and the open web. HLS historically used MPEG-TS segments; both now support fragmented MP4 (CMAF), which lets one set of segments serve both protocols.
Which should you use?
Both. Because iOS effectively requires HLS and much of the rest of the ecosystem leans DASH, shipping only one leaves a gap. With CMAF you package the media once and expose two manifests, so “HLS vs DASH” stops being a choice.
How rehelios handles it
rehelios produces adaptive HLS from every upload and MPEG-DASH alongside it, from a single file — so playback works on an iPhone, an Android tablet, and a smart TV without you picking a format or running a packager.