VDR needs a DVB tuner for receiving TV signal from satellite, cable or terrestrial transmitter. DVB-S card is for receiving digital signal from satellite, DVB-T is for receiving digital signal from terrestrial transmitter and DVB-C is for receiving digital signal from cable. VDR can use also analogue cards. It is also possible to receive signal with VDR server and stream it to client.
V4L-DVB Wiki has good list of DVB cards at http://www.linuxtv.org/wiki/index.php/Hardware_Device_Information