First of all, let’s explain shortly what HLS is.
HTTP Live Streaming (also known as HLS) is an HTTP-based media streaming communications protocol implemented by Apple. Since it requires only standard HTTP transactions, HTTP Live Streaming is capable of traversing any firewall or proxy server that lets through standard HTTP traffic, unlike UDP-based protocols such as RTP. This also allows content to be delivered over widely available CDNs. In a few words, HLS works by breaking the overall stream into a sequence of small HTTP-based file downloads. At the start of the streaming session, the client downloads an extended M3U (m3u8) playlist containing the metadata for the various sub-streams (called TS files) which are available. You can read more about HLS Architecture on Apple Developer website.