Color Models
A color model is a method of representing colors in a video or image using data. This guide will be covering the most widely used color models.
RGB
RGB is probably the most well-known color model, and is primarily used in image encoding. RGB consists of three color channels, Red, Green, and Blue, which are then combined to determine the final color of each pixel. Typically, RGB is the final model that a monitor or TV will use to display images, although it is not commonly used for video encoding.
YUV
YUV, also known as YCbCr, is the most widely used color model for video encoding. It consists of three components: Y aka Luma, which represents luminance or brightness, and two chroma planes, which represent color. Generally a video player will have to convert a YUV video into RGB before it can be rendered, but there are significant compression benefits to using YUV over RGB for video.
The most notable reason to use YCbCr is an optimization called chroma subsampling. This means that the chroma components can be encoded at a lower resolution than the luma components, which results in a smaller output file. You can read more about chroma subsampling in Color formats.