What is the name of light that people can see?
The light that people can see is called visible light. In order to understand light, one must first understand what light is.
Light is actually electromagnetic radiation and is a very small region of the larger electromagnetic spectrum. The electromagnetic spectrum is a range of all the possible frequencies of electromagnetic radiation. These frequencies are classified into a number of different categories based on wavelength.
These categories (from shortest to longest wavelength) include gamma radiation, X-ray radiation, ultraviolet radiation, visible radiation (light), infrared radiation, terahertz radiation, microwave radiation, and radio waves.
Because of the way the human eye developed evolutionarily, we can only interpret a small portion of the spectrum as visible light. This portion is electromagnetic radiation with a wavelength between 400-700 nanometers. Interestingly, some other animals can see a broader range of the spectrum, and are able to detect ultraviolet and infrared as well.