Description by Wikipedia
The Plex Media Server scans and organizes your media, then lets you stream it to all of your devices. It’s the central, most important piece of Plex. Once installed, it gets to work scanning and cataloging every piece of media, making it look beautiful and intuitively organized.
A premium version of the service, called Plex Pass, is also available and offers advanced features like synchronization with mobile devices, access to cloud storage providers, up to date and high quality metadata and matchings for music, multi-users mode, parental controls, access to high quality trailers and extras, wireless synchronization from mobile devices to the server, access to discounts on partner products and early access.Set Up Your Free Account