It is the width-height dimensions of an electronic display device, in pixels. Electronic display device is used for presentation of text, images or videos. Example: TV, Computer monitor, Smartphone etc.
Screen Resolution means the number of horizontal and vertical pixels on a display screen. A higher display resolution in a display of the same size means that displayed content appears sharper.
Video Graphics Array (VGA) is the standard monitor or display interface. The VGA standard was originally developed by IBM in 1987 and allowed for a display resolution of 640×480 pixels (4 bits per pixel and a 4:3 aspect ratio). In the field of videos the resolution of 640×480 is called Standard Definition (SD) – in comparison for instance to High Definition (HD) (1280×720) or Full HD (1920×1080).
Super Video Graphics Array (SVGA) is the regular VGA modes and 800×600 pixels.
Quarter Video Graphics Array (QVGA) (320×240) is half the resolution in each dimension as standard VGA. Normally used when describing screens on portable devices (Example: pocket media players, cellular phones, PDAs etc.)