Simply put, it refers to a video resolution with 480 lines of vertical pixels and 854 pixels horizontally, with the “p” standing for progressive scan. This means that the lines are displayed sequentially from top to bottom, rather than interlaced as two separate fields. In practical terms, 480p resolution contains a total of 480 x 854 = 480,360 pixels, with a widescreen aspect ratio of 16:9.
While this provides reasonably clear standard definition images and video, it does so while maintaining smaller file sizes and lower bandwidth usage than higher resolution devices such as high-resolution security cameras. It is widely considered the minimum resolution for an acceptable widescreen viewing experience, setting the standard for many analog broadcasts, DVDs, and older video content.
Read also: 480p Resolution: Why It Still Matters Today