4:3 is a typical aspect ratio for television and video. Where, 4 refers to the width of screen and 3 is the height.
Images-aspect ratio 3
Earlier when moving images were put on film for the first time, the aspect ratio 4:3 was used. And it became an Academy standard. This aspect ratio was used till 1950s.
Frame sizes in 4:3 Aspect Ratios commonly used are:
• PAL : That is 768 x 576 (used for TV)
• VGA : That is 640 x 480 (used for web)
Images-aspect ratio 4