Standard definition television

Standard definition television or SDTV is one of the formats used in digital
television broadcasting.

SDTV can be broadcast in 704 pixels × 480 lines (16:9 and 4:3 ratios)
or 640 pixels × 480 lines (4:3 ratio). The refresh rate can be any of
24, 30 or 60 pictures per second.

SDTV in 4:3 aspect ratio has the same appearance as the regular analogue TV
(NTSC, PAL, PAL2, SECAM) minus the ghostly, snowy images and static noises.