a) The new HDTV standards call for a range of different resolutions. Those that are higher than today’s NTSC are considered HDTV. The ones that are comparable to NTSC are considered SDTV. Because SDTV is component and digital, it will still be higher quality than NTSC. b) This term is used to signify a digital television system in which the quality is approximately equivalent to that of NTSC. Also called standard digital television. See also Conventional Definition Television and ITU-R Recommendation 1125.