Rec. 709 is a standard for high-definition video that defines the color space, resolution, and frame rate for HD content. It was established by the International Telecommunication Union (ITU) and is widely used in television and film production. The standard specifies a resolution of 1920x1080 pixels and a frame rate of 24, 30, or 60 frames per second. The color space of Rec. 709 is designed to match the capabilities of typical HD displays, ensuring consistent color reproduction across different devices. It uses a specific set of primary colors and a gamma curve to achieve accurate color representation, making it essential for content creators and broadcasters.