How is a "video signal" defined in electronics?

A "video signal" is best defined as a baseband signal that includes visual information. Baseband refers to the original frequency range of a signal before it is modulated. In the context of video signals, this means the signal carries the necessary information to represent an image directly without modulating it onto a higher frequency carrier wave.

This definition is crucial because video signals consist of information that outlines brightness (luminance) and color (chrominance), forming the images we see on screens. Understanding that a video signal encompasses all visual data in its raw form helps clarify its application in different contexts, such as broadcasting, recording, and video display technologies.

While options mentioning analog signals, composite signals, or digital signals with specific characteristics touch on aspects of video transmission, they do not capture the comprehensive essence of a video signal as a baseband representation of visual information. This highlights the specific requirements for capturing and transmitting the image accurately, as characteristic of video technology.