Here’s answers to each of your questions:
Whats the difference between the CDN link and the Render link?
The Render link is a temporary file that gets created for every render. You can download the file from that URL and move it to any hosting or storage service you like, i.e. YouTube, Google Cloud, Vimeo, etc… or your own web server or to your desktop.
The Render link file is deleted after 24 hours. It is also not suitable for streaming as it is not behind a CDN.
All rendered files are also transferred automatically to our CDN hosting service where they are stored permanently until you delete them. These files are suitable for streaming, and yes, you can think of this as a simple on demand streaming video host.
If you use your own hosting provider or service you can opt out from sending your videos to the CDN hosting service, more info here: Opt-out from Shotstack Hosting | Shotstack Documentation
There are also a couple of built in destinations where you can send your files instead of doing it yourself, see here: Distribute Assets Using Destinations | Shotstack Documentation.
Are either of these considered to be a streaming video host?
The file at the CDN link is the Shotstack hosted file and, yes, you can consider this a streaming video host. It is best suited for short videos with a low number of views expected, i.e. for personalised or short lived videos.
If you have longer videos that will receive many views over a long period and need more advanced features like hls or adaptive bitrate then consider the Mux integration: Mux Destination | Shotstack Documentation.
Whats the recommended embedded player setup on my site so that I can stream the file?
Most off the shelf players will serve our CDN files just fine. It is just on demand video using a single file, no hls or anything fancy. We use https://plyr.io/ in our demos but other suitable players would be https://videojs.com/, https://www.jwplayer.com/ or even just the browsers html
Our complete hosting guide is here: Host and Serve Video and Images | Shotstack Documentation
I hope that answers your questions and clarifies how it all works.