M3U8 is a playlist format used by various audio and video playback programs, it contains a path or URL to a media file or folder of media files, along with information about the playlist. This player downloads the video specified in the M3U8 file and plays within your browser. To get started,

• Paste a m3u8 URL into the above input box (skip if pre-filled);
• Click the "Play" button.

HLS stands for HTTP Live Streaming. It's a HTTP-based media streaming communications protocol implemented by Apple Inc. It works by breaking the overall stream into a sequence of small file downloads, each download loading one short chunk of an overall potentially unbounded transport stream.

HLS streams are usually described using M3U8 playlist.

"CORS" stands for Cross-Origin Resource Sharing, which is a security feature implemented in web browsers to restrict web pages from making requests to a different domain than the one that served the web page. When the HLS player attempts to load a m3u8 file from a different domain, the browser checks if the server hosting the resource includes the "Access-Control-Allow-Origin" header in its response. If the header is not present or does not include the requesting domain, the browser blocks the request and returns the "No 'Access-Control-Allow-Origin' header is present" error.

To fix this error, you need to add the "Access-Control-Allow-Origin" header to the server's response. This header should include the domain name of the requesting page or "*" to allow requests from any domain.