The term "High Definition," commonly abbreviated as HD, refers to a video or image quality that is significantly higher than standard-definition (SD) formats. High-definition images and videos have more pixels per inch or frame, resulting in greater detail, clarity, and sharpness compared to SD formats. This means that high definition content appears much smoother, with finer details and richer colors, making for a more immersive viewing experience. HD is typically associated with resolutions of 720p (1280x720) or 1080i/p (1920x1080), although there are other standards that can also be considered high-definition, such as 4K and 8K.