HD stands for High Definition and it refers to a higher resolution video format compared to standard definition (SD). HD video provides a sharper, more detailed picture with a resolution of either 720p (1280 x 720 pixels) or 1080p (1920 x 1080 pixels). The increased resolution in HD video results in a more immersive and visually stunning viewing experience. With the advent of 4K and 8K resolution, HD is becoming less common, however, it is still widely used and supported in many devices.
There are several video resolutions used in modern displays and devices. Some of the most common video resolutions are:
Standard Definition (SD) - 720 x 480 pixels (NTSC), 720 x 576 pixels (PAL)
High Definition (HD) - 720p (1280 x 720 pixels) and 1080p (1920 x 1080 pixels)
Full High Definition (FHD) - 1080p (1920 x 1080 pixels)
Quad High Definition (QHD) - 1440p (2560 x 1440 pixels)
4K Ultra High Definition (UHD) - 2160p (3840 x 2160 pixels)
8K Ultra High Definition (UHD) - 4320p (7680 x 4320 pixels)
It is important to note that not all devices or displays support all resolutions, and the resolution that is used depends on the capabilities of the device and the content being displayed.