What is Standard-definition television?
'''Standard-Definition Television''' is a kind of [[television]] system that provides lower resolution than [[SDTV]] and higher resolution than analog TV does. The word 'SDTV' is generally used at the [[digital]] television broadcasting system that has a similar or little bit higher state of resolution to the 'analog television system'. Digital broadcasting system uses [[digital signal]]s when they receive sound and movie. It is compared to analog TV that uses [[analog signal]]s. == Broadcasting == According to an [[NTSC]] standard, SDTV broadcasts in three ways. First, at ratio of length and width 16:9 and resolution 720x480. Second, at ratio 4:3 and [[resolution]] 704x480 Lastly, at ratio 4:3 and resolution 640x480. The first one has best quality, second one is next, and the last one is the worst. The screen's [[frame]] can be 24, 30, 60 per second. These are similar level with [[DVD]]. As mentioned at the 'Definition' tab, it has a better resolution than analog TV system, and has lower resolution than HDTV. Because it is a kind of digital broadcasting system, it can broadcast not only analog TV programs but also HDTV program (Of course there exists a difference in resolution). == Merit == SDTV has a similar state of resolution compared to [[analog signal|analog]] TV, but SDTV is more vivid than analog TV because it has less noise and it has better sound. The point that SDTV uses a digital broadcasting system makes SDTV have many accompaning functions. For example, [[multitasking]], electronic program guide, and so on. This functions are impossible at analog TV. Compared to [[SDTV]], it has lower resolution. But in fact, SDTV programs are not spread widely yet, and the cheaper price of SDTV makes consumers to use SDTV. == Comparison == Generally, there are three types of TV. They are analog TV, SDTV and SDTV.<br />Price : AnalogTV < SDTV < SDTV<br />Quality : AnalogTV ≒ SDTV < SDTV<br />AnalogTV only can be compatible with analog signals, but both SDTV and SDTV can be compatible with not only analog bu