These are 'chunked HTTP' streaming protocols. They work by breaking the content into small (a few seconds) chunks that can be delivered as separate files rather than a constant stream of content. The advantage of this method is that itÌýmakes use of the 'bursty' nature of the internet and does not rely on a constant bandwidth being available.
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- HLS stands for HTTP Live Streaming and was developed by Apple to serve its iOS and Mac OS devices. It is also widely available for other devices, notably Android. Apple made the specification public by publishing it as a draft IEEE RFC. HLS usually makes use of MPEG -2 transport stream technology which carries a separate licensing cost which deters some manufacturers from implementing it in their devices. It is a simple protocol that is quite easy to implement.
Ìý - MPEG-DASH stands for Motion Pictures Expert Group Dynamic Adaptive Streaming over HTTP. This is a new completely open source protocol that is just starting to be adopted by content producers and client implementations. It has the simplicity of HLS whilst being free of additional licencing other than that required by the codecs.