16:9 (1.77:1) is a widescreen aspect ratio with a width of 16 units and height of 9 units.
Once seen as exotic, since 2009 it has become the most common aspect ratio for movie screens, televisions and computer screens. It is the international standard image format for digital television and is also used in many smartphones. In home use and for entertainment it has replaced the old "fullscreen" 4:3 aspect ratio.
"A Brief Review on HDTV in Europe in the early 90's | LIVE-PRODUCTION.TV". www.live-production.tv.