Capture Cards, how do they work?

Question

I know that you use a capture card to record tv, but what do you need for that? Does the capture card nee to be hooked up to your cable line or does it run of satelites? Oh and can you take video stills too?

Answer 1

Most video capture cards do have tuners. Make sure you buy a card with a Digital Tuner, since analog transmission is going away soon.
So, in the US you need NTSC/ATSC/Clear-QAM and it covers off-the-air and cable. No cards support satellite.
The cards have also composite/s-video inputs and outputs.

Video still capability is more of a software feature. Even Windows movie maker allows you to take stills from your input source.