Cam - Conditional access module
Picture here:
<a href="http://www.satron.co.uk/prod_astoncam.htm" target="_blank">http://www.satron.co.uk/prod_astoncam.htm</a>
Most of the Integrated televisions come with a slot in the back of the television into which you slot a cam, in laymans terms you could think of the cam as a translator and card holder, it translates the signal you receive checks the card to see if you are authorised to view and forwards the information it to the decoder,
A few integrated televisions are around which come complete with the cam, Matsui was one but it is no longer being produced, As I understand it most of them now do not come with a cam, and to get one you sign up with I** Dig and they supply one free.
What I am not sure about is whether you can buy a suitable cam from a supplier without having to sign up with I** Dig, maybe someone with more knowledge than me could answer that bit.
Once you have your television complete with cam yes you can use a Gold card