3. 1998: HDTV
High-definition television had been in the works for at least 30 years before the first HDTV set made its way to market in 1998. There were also TV sets labeled "high-definition" as early as the 1930s, although many of them wouldn't measure up against standard definition sets today.
Modern HDTV sets have a wider screen, allowing them to play widescreen films without cropping or letterboxing. On top of that, they display the picture at a higher resolution than their standard-definition counterparts. Naturally, this means that programs must be shot in high definition to be played back in HD, so the prevalence of HDTV is affecting the production of TV shows. HDTV has also led to high-definition playback technologies, like Blu-ray and HD-DVD. And in the United States, HDTV has been one of the driving forces behind the switch from analog signals to digital. Digital signals mean more bandwidth, which means more room to carry HD programming.
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