As technology marches on, consumers are faced with an ever greater number of choices for television entertainment. HDTV and satellite TV are two of the most important developments that have come onto the scene in the last decade or so. Although HDTV is a topic I enjoy discussing, the focus of this article is going [...]

what does this mean
Optional set-top box required for high-definition cable or satellite programming
it also says
Built-In HDTV Tuner: Add HD-capable antenna to receive over-the-air high-definition broadcasts
do you need to buy another tuner?
or is the optional some box the cable company gives you?