A Stream Link is literally a link to the content on the website of a provider. You can use them in any browser or in the Channels apps. Be sure to read the documentation, especially the Troubleshooting & FAQ since these questions are answered there and provide important information and context for what you are going to get.
Content on providers is not static and changes multiple times a day. You must bookmark the programs you want and SLM hunts them down for you. But I'd direct your considerations to this: