Display size is the measurement of usable display screen. All display size are always scaled length wise diagonally. Most of the them are denoted in inches. Resolution of a screen is different from Screen size. Screen size is a physical standard calculation. While resolution is the number of pixels put into that screen. Pixels are tiny dots that represents required color to the display. Increase in number of pixels per inch (PPI) increases the sharpness quality of the display.
Sometimes the ratio of the screen is given similar to 5:4, 16:9. They are the ratios of Width and Length. The are helpful in calculating the display height and width.
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