Most husbands these days have already convinced their wives of the need for high-definition television, so most wives wake up every day to a giant rectangular monstrosity mounted on their living room wall. People already understand that 1080P and 720P are designations for types of HD video displays.
Most people also recognize that the number refers to image clarity, the higher the number, the better the image. This is mostly correct as a starting point. 1080P, 720P and 480P are all common ways to describe resolution.
The "P" stands for "progressive," which simply means the full frame, but isn't relevant enough for the layperson to go into much detail here. It should be noted, however, that progressive refers to a sequence of fully formed still images, one after another, much like frames in traditional film. The number refers to the vertical number of dots, or pixels, that make up the image. 1080P means 1,920 dots long by 1,080 dots high, for a total of over 2 million dots.
These two million plus dots make up the image, and the more dots there are, the clearer and sharper the image will be and the less jagged the edges of objects will appear.
The old standard definition video (from the 90s) was only 720 dots long by 480 dots high, with a total of only about 300,000 dots. It's easy to see why a much clearer and larger image can be made from 2 million dots compared to 300,000 dots.
However, it's important to note that resolution refers to two separate things: display technology and native video resolution. It's crucial to make this distinction.
In most cases, video professionals are referring to the resolution of the video footage itself, not the display it will eventually be played on. They are talking about the image size of video files shot by the camera or created in a computer as an animation.
This is typically the resolution of the final edited video created from the footage and what ends up being broadcast or streamed online. If a 480P video is played back on a 1080P HD television display, it will not make it look like high-definition video.
The resolution of a video is first defined by the video file itself, and to be seen in all its glory, it must be played back on a display that supports that resolution.
There's another format coming soon called 4K, which is essentially ultra-high definition. 4K footage consists of about 9.5 million dots per image, 4-5 times as much image information as 1080P HD.
In conclusion, video size refers to two separate topics: file size (this deals with compression) and image size (resolution). Video resolution is defined by the number of dots, or pixels, that make up the image. The more dots, the larger and clearer the image will be. Video resolution refers to two separate things: display technology (such as your TV or computer monitor) and the resolution of the video file itself. The latter is typically what most video professionals are referring to.
