Real debrid and similar services act A) as a multi premium account (so you can download from sites like Mega or Rapidgator etc like you had a premium account for those services) and as a torrent downloader just like webto and such. You paste a link to them and they download it from a torrent and make it available to you for download/stream via regular https.

Whenever someone downloads a Torrent, the debrid service will cache it, the user who queued it wouldn't be able to download it otherwise of course.

Yet, from that moment on, the debrid service will serve the cached file whenever someone queues that same Torrent instead of downloading the same file over and over again, so it becomes available to you instantly. That's how torrentio and sich can use debrid services to instantly start a Video stream via Plex or Kodi or Jellyfin or Stremio.

The Downloads you accessed through them become available via your account, so you can even mount the service via rclone and access the downloads like they were on your local filesystem.

So it's basically webto just with the added bonus of Instant completion to many torrents.