Hypertext Transfer Protocol Live Streaming (HLS) is a streaming protocol developed by Apple that is based on HTTP. A streaming protocol is a standardized format for delivering multimedia content. Streaming protocols define how content is sent from one device to another and how they are reassembled into playable content. The main innovation of HLS was to provide the videos in adaptive bitrate. Instead of using a single video file, HLS separates a video into many small parts. The video quality can be automatically adjusted if the available bandwidth is too low. In detail, if the upcoming parts have not been downloaded in high quality yet, the video quality is automatically lowered to avoid buffering times.
Without HLS, streaming would be very different today. We would still struggle with permanent buffering and quality issues whenever our connection got worse for a few seconds or needed to handle a bigger request. HLS was also a breakthrough in modern streaming technology. After Adobe protocols and players had been the standard for a long time, their technology was more or less overtaken by innovations like HLS or HTML5. A significant advantage is that it brings the possibility of specifications. So users can better adapt them to their needs. They are also considered to be more secure, faster, and more reliable than older technologies.