Widescreen images are displayed within a set of aspect ratios (relationship of image width to height) used in film, television and computer screens. In film, a widescreen film is any film image with a width-to-height aspect ratio greater than the standard 1.37:1 Academy aspect ratio provided by 35 mm film.

For television, the original screen ratio for broadcasts was in fullscreen 4:3 (1.33:1). Largely between the 1990s and early 2000s, at varying paces in different nations, 16:9 (1.78:1) widescreen TV displays came into increasingly common use. They are typically used in conjunction with high-definition television (HDTV) receivers, or Standard-Definition (SD) DVD players and other digital television sources.

With computer displays, aspect ratios wider than 4:3 are also referred to as widescreen. Widescreen computer displays were previously made in a 16:10 aspect ratio (e.g. 1680 × 1050), but now are usually 16:9 (e.g. 1920 × 1080).