Based on MPEG2-TS, HLS (HTTP Live Streaming) is Apple’s patented streaming format. It is an adaptive streaming communication protocol. Initially, HLS was used only for Apple devices. Now it is supported by other devices like Android-based smartphones.
HLS works by splitting live streams into a sequence of smaller HTTP-based file downloads. Each download loading one small portion of an overall potentially unbounded transport stream. As the stream is played, the client may choose from several different alternate streams containing the same content encoded at a variety of data rates. This allows the streaming session to adjust to the available data rate. It downloads an extended M3U playlist at the beginning of the streaming session, which contains the metadata for the different sub-streams which are available. As an HTTP-based technology, no streaming server is required, so all the switching logic resides on the player.
HLS can distribute both on-demand and live video files. HLS uses the HTTP protocol. Hence, instead of using a specialized streaming server, users can stream media from their regular web server.