Media Server
Media Servers are a fixture type that could be characterized as virtual fixtures, but it is software being controlled often on dedicated hardware.
Media servers can take up an massive amount of attributes. Some media servers use several DMX universes. It is also in media servers that attributes using 3 DMX channel appear (24-bit control).
Every media server is different. Some are flexible with their configuration, others have a fixed set of attributes.
Most are configured around a set of (video) layers, that needs to be patched. Some have master layers and even camera layers.
Other elements in media servers could be pixel mappers, 3D mapping/warping, sound, effects, particle systems, and so on.
It can be very complex to create good fixture profiles for media servers.
Selecting the Media Server fixture type does not necessary assign a class to the fixture profile. Since the server is not visualized as a fixture in MA 3D, then this OK. The video output from the server might be used as a CITP stream into the MA 3D (read more about CITP in the Using CITP topics).