Well think of it like this lets say this wasn't and security system and it was a video game console and remote.
Now the console or keypad or the main components the power on or shut off the devices and the remote or sensors are the secondary parts but they are needed to help the console or keypad figure out what they are doing.
Answer:
a computer that requests a service.
Operating systems.
Device drivers.
Middleware.
Utility software.
I suggest you get a adapter from the old video input to HDMI
I would say 3-D model!!!! not 100% sure but this sounds most correct!