Well of course, the first component needed is the HDTV signal which is sent from a source like a cable or satellite provider, or a local broadcast station. It takes more advanced and expensive equipment to be able to broadcast a HDTV signal instead of the old analog signal that has been used for many years. But the FCC has mandated that by the end of 2006 all broadcasts will have to be available in HDTV, so it won't be long before HDTV will be the defacto standard for sending and receiving TV signals. In fact, most of the major cable and satellite companies already offer significant HDTV programming options at this point.
Now that there is a HDTV signal being sent you will need a HDTV "enabled" or "ready" television to be able to receive that signal and display it correctly. If the TV is "HDTV enabled" that means that it does not have a HDTV tuner already built into it but can display HDTV programming if a HDTV tuner is hooked up to it. If it is "HDTV ready" it has the HDTV tuner and is capable of receiving HDTV signals right away. So what is the difference for you?
Well, most satellite and cable companies will only allow you to use their proprietary tuner to gain access to their https://vimeo.com/54173025 programming on your TV set, so they essentially bypass the tuner that is in the TV. If you have a HDTV enabled set, this is no problem because it is able to receive and display in HDTV using the tuner from the satellite or cable company. If you have a HDTV ready set, it is still no problem, but if you paid extra for the tuner, you may not be able to get much use from it if you view satellite or cable programming all the time. However, if you are not able to get local channels by satellite or cable, having a HDTV tuner can allow you to receive those channels and display them in HDTV with an appropriate antenna.
So when you look for a new television, be sure to have in mind what your needs will be regarding programming. If all of your viewing will be done through a cable or satellite provider there may be no need to get a TV set that has a HDTV tuner built in. It just has to be HDTV enabled and ready to process a HDTV signal when a HDTV tuner is attached to it. On the other hand, if you will be receiving your broadcasts by antenna or over the air, then you will definitely need the built in HDTV tuner to receive and display HDTV programming.