In physics, light refers to electromagnetic radiation. The light we normally talk about in everyday life refers to the visible spectrum (the part of the electromagnetic spectrum that the human eye can see).
Other animals can see parts of the spectrum that humans can’t. For example, a large number of insects can see ultraviolet (UV) light.
UV light can be used to show things the human eye can’t see, coming in handy for forensic scientists.
The wavelength of infrared light is too long to be visible to the human eye.
Scientists study the properties and behaviors of light in a branch of physics known as optics.