Plex and Jellyfin organize your media using metadata and it’s pretty much your own Netflix, Hulu type thing.
However, if you get a Plex pass you can stream your media outside of your network to friends and family. Or just yourself when you’re out of the house. But your PC would need to stay on, unless you have a NAS bay with the hard drives in it.
Not like kodi. There are channels to watch stuff for free, kinda like Pluto TV. However, I do think you can stream your own content from your PC using kodi, not sure though.