16:9 (or widescreen) is the ratio with the width of 16 units by the height of 9 units.
In the early 21st century, widescreen became the conventional video aspect ratio for HDTV, SDTV, and computer monitors and it is often used in smartphone screens.
References
change"A Brief Review on HDTV in Europe in the early 90's | LIVE-PRODUCTION.TV". www.live-production.tv.
