A browser cannot read another site's pages, so the link goes to this site's server, which finds the video with yt-dlp. The file itself then comes straight from the site to your browser wherever the site lets other sites read its files, as X, Bluesky, SoundCloud and Imgur do. YouTube, TikTok and Twitch do not, so for them the server passes each stream on as it arrives, without keeping it. Joining the picture to its sound, or converting to mp3, happens in your browser. Only what your browser cannot finish (a stream in pieces that the site will not hand to it, a file over 1 GB) is made on the server, which deletes it within the hour.

Videos that need an account, live streams, videos over three hours and files over 4 GB cannot be saved here. Save only what you have the right to keep.