You'll need to download Plex Media Server in order to use this streaming service for your own files. If you want to manage everything the best way possible, you'll have to create an account and use it on your devices to synchronize your library wherever you want to use it. It's a must-have app for using all the possibilities Plex has to offer. Through this app, you can manage all the multimedia files you have, as well as organize the different folders where they're stored. Once you've installed Plex Media Server, the program runs in the background on your Mac so you can enjoy all its features. It's an incredibly useful program that makes your files accessible from other devices, whether it be another Mac, PC, smartphone, tablet, console, Chromecast.
Plex Media Server is an app that lets you create and manage a multimedia server from your own Mac.