kind of a broad question. this device, when it is supported will allow for HD from acable box or a sat provider, which will allow for "premium" channels. For the time being , many are using the HDhomerun which is a dual QAM tuner. It will receive over the air "local" HD, or QAM which is how several cable compaies are relaying the local HD content unencrypted over the wire.
Shaun