The biggest difference that I know of is a tv has the tuner and speakers. I know some monitors have speakers but they are powered by an outside source and not usually adequate for 'tv watching' in a living room area. I think the contrast ratio and brightness are different between the two. There is that whole 1080i 1080p 720 that monitors are not graded by.

Anyone out there correct me if I am wrong but a monitor would work if only the viewing part of a home theater system. I am unsure how a monitor would hold up to 'tv' type viewing over a long period 'years'.

The problem may arise in matching the input jack type. TV's have different inputs from computer monitors.
TV: Component RGB, S-Video, HDMI, RFI (analog cable, antenna) inputs.
Computer: serial VGA, or DVI.
Now, there's an adapter for DVI to HDMI, but there's no audio in DVI, AFAIK.
Tuner-lacking TV screens are referred to as Monitors, but from a Video standpoint, not a computer one. IOW, they are intended to be used in home theater situations with accompanying cable boxes, playback devices, and audio systems.
Casey

DVI is video only.