In 1080p or 720p videos, ‘p’ means Progressive Scanning. Progressive Scanning is one of the methods used to display an image on a screen. The other one is called Interlaced Scanning. Progressive scan is a display and signal type in which the entire image is refreshed every cycle. To understand Progressive Scanning, first, a little background knowledge is necessary.
Today’s advanced technology allows High Definition (HD) display in latest TV sets and streaming services like Netflix. The detail level of a screen is defined by High Definition. To understand HD more clearly, a term ‘pixel‘ is used. A number of pixels are used to display an image. A pixel is the smallest visible element on a display. To show an image, if there are more pixels in use, the image will become sharper. See the following image:
A 1080p TV uses 1080 lines or pixels (vertical) and 1920 lines or pixels (horizontal) to display an image. On the other hand, a 4K TV uses 2160 lines or pixels (vertical) and 3840 (horizontal) lines or pixels, resulting in a much sharper image. The method to draw these lines is either interlaced or progressive. Progressive scan allows drawing these lines at a time in sequential order. For example, an entire single frame image is displayed every 1/60th or 1/120th of a second (refresh rate-faster is better for image), allowing a much faster rate compared to interlaced scan.