Here is a table showing the characteristics of different Television Systems in the world. TV System total lines horizontal freq. A bit of historical levity. The French came up with their own system and the British thought of reaching the best trade-off with theirs. This gradually builds an image on the screen and must be done at least 50 times per second for the human eye to perceive an unbroken image.
TV transmission is now an 'old' technology.
The horizontal signal is a modulated wave where the modulation carries information about the picture and its color. By increasing the vertical frequency we increase resolution - however, at the same time the horizontal frequency must also be increased otherwise there would be flicker. In fact an SVGA signal has a vertical frequency varying from 45 to 72 Hz and a corresponding horizontal frequency of 31.5 KHz. An image can be displayed in two modes, interlaced and non-interlaced. This refers to the way an electron beam that creates the image is moved horizontally and vertically across the screen.