You talk about light as if it were a person carrying a clip board writing down things on its way to you. It is a physical phenomenon that gets affected as it propagates.
Depending on the various processes that it goes through before it reaches your eye, its amplitude,polarisation, frequency (or wavelength), pulse time etc. get affected from which we can ...
Light may carry information defined by which frequencies of the light spectrum it has, for example the colour of an object is information carried by light, white light from the sun is actually many different wavelengths combined to create "the colour white", these wavelengths can teach us about:
-What object it got reflected off of
-What created ...
Let me first deviate to radio&television: a radio wave with constant frequency does not carry information, since it is absolutely predictable on the basis of a few parameters: its amplitude, its frequency and its initial phase:
X(t) = A\cos(\omega t +\varphi)
The information is encoded into the wave by modulating these parameters, i.e. by changing ...