A collection of thousands and millions of stars is called a galaxy.
Supplementary
Quantification, although the collection process could be called data collection (just a guess :)
yes, it is...................
space
A collection of rays is called a ray bundle.
A collection of rays of light is called a beam or a ray bundle.
rainbow
The collection of wavelengths is called the electromagnetic spectrum. It includes all forms of electromagnetic radiation, from radio waves to gamma rays.
The electromagnetic spectrum.
Light rays coming in are called incident light rays.
they are called UV, or Ultraviolet rays.
At collection of stamps is refered to as a stamp collection. They are frequently kept in albums. Philately is the name for the study and collection of stamps.
The light rays that bounce back are called reflected light rays.
a collection of fish is called a school of fish
it is called a range of mountains
A collection of sayings is called a "proverb" or "aphorism."