The term HD is an acronym for high-definition. HD refers to the resolution of an image or video. A picture or video with a high-definition resolution means that it is displayed in a format composed of 1280×720 pixels (720p) or 1920 x 1080 (1080i or 1080p). This gives a clearer and sharper image compared to anything that is in standard format.
HD is gaining popularity. More and more TV networks are providing HD programming to their viewers. However, to see these HD programming viewers should be aware that they need to have a high-definition TV. This is why it is important to know the difference between HD-ready TVs and HDTVs.
HDTVs are fully capable of receiving HD programming without an additional device if and where HD programming is available. This means that if a local channel airs programming in HD, someone with and HDTV will be able to see it in HD.
On the other hand, an HD Ready TV needs an additional device to be hooked to it to be able to get high-definition reception. Note too that for cable and satellite subscribers, having an HDTV and getting HD programming is not enough without using non-HD cables, so make sure that you are using and HDMI cable and not the regular RCA or coaxial cable–they will not transmit the signals in HD.