J. River Media Center includes several servers.
Library Server, formerly called Media Server, can serve a media collection on one PC, so it can be played with another copy of MC on another PC anywhere on the Internet.
Tivo Server can serve MC's library to a TiVo.
UPnP Server can serve MC's library to a UPnP device, sometimes called a Media Receiver.
Remote Server is a small web server built into MC, and allows MC to be controlled from a web browser running on another PC.
The first three servers are located in MC's tree, under Services and Plug-ins, and that is where they are configured.
Remote Server is configured in MC's Options under Startup.