in your opinion, what are the sub- system of the PC-based dvr.

i have to analysis this system and i have to do analysis only 5-6 main sub-system of the whole system.
but now i have no idea that what are the sub-system of this system.

Uh, What?

Honestly, you just confused the hell out of me.

You got to be more clear on what you are asking

does he mean what software controls the boards, or what the programming is that is on the board?

Got me!!!!

It sounds like you are asking about the OSI Model for a pc based DVR system.

Here's a guess:

-The video capture card (which converts the analog camera signal to digital)
-The bus where the various video cards reside.
-The storage system (aka hard drive)
-Other inputs and outputs, including keyboard and monitor
-The Motherboard, which links the Bus, the storage system/HD, the IO ports (keyboard and monitor) with the CPU.

You still got me