Sizing Up Screen Differences: What Is the Difference Between Square and Widescreen Monitors?
Historically, computer displays, like most televisions, used a standard aspect ratio of 4:3, which was the also original standard for movies. This meant that the ratio of the width of the display screen to the height was 4 to 3. But as television makers started to design "High-definition" TVs (HDTVs) - with new standards built around a wider aspect ratio to better accommodate modern film, and with the advent of digital broadcasting in television - the movement from square (4:3 and 5:4) to widescreen (16:9 and 16:10) began. One may have noticed this transition as it first started to appear in televisions, then in laptops and later in standalone monitors.