No. It’s not a replacement for the server. It’s only a player with alot of options. You will still need the server program installed.
It’s more of a replacement for “Plex Media Player” which may or may not be at it’s EOL.
Plex Media Player.
https://www.plex.tv/blog/introducing-the-plex-media-player/
New Plex app
https://www.plex.tv/blog/desktop-af/
Words from the CTO and Co-Founder