DTV is HDTV
Where were you during the big digital television (DTV) switch of 2009? If you had a newer television with a digital tuner, or you had digital cable or satellite TV, you probably didn't notice anything different.
However, if you had an older TV and watched over-the-air broadcasts by antenna, you may have been one of millions unprepared for the June 2009 switch. That's when the Federal Communications Commission (FCC) in the United States required all over-the-air television broadcasters to switch to digital television (DTV) broadcasting.
Despite early misconceptions, this didn't necessarily mean you needed a new TV set to continue watching television. And you certainly didn't have to have an HDTV set. In fact, unless your television has a built-in digital tuner, receiving DTV requires only a digital-to-analog converter to turn the digital signal into an analog signal that your current TV set can show. While this does reduce the quality of the original digital signal, you can still watch all available over-the-air broadcast TV in your area without a new TV purchase.
But DTV isn't the same thing as HDTV. While digital television supports HDTV, not all channels are broadcast in high definition and not all shows are produced in HD. As each channel and program transitions to HD format, though, digital broadcasting ensures that we can receive digital HDTV over-the-air broadcasts when they're ready.