DSS, Digital Satellite System, is the next step in Television after Cable TV. More channels can be viewed through DSS than through the coaxial cable of Cable-TV. DSS is a pure digital signal using the MPEG-2 satndard video compression so there is room for interactivity through the DSS than through the analog setup of Cable-TV. It is will also be able to support video on demand and other interactive possibilites. With only an 18 inch satellite dish to mount outside, a descrambler, and a couple cables to connect everything, it isn't hard at all to setup.
The DSS Services send out digital signals from geosyncronous satellites out in space down to a DSS dish using the high frequency "Ku" band rather than the "C" band used for the larger Satellite dishes.