Do you really understand Einstein’s theory of relativity? - BBC News
General relativity explained in under three minutes
Einstein Theory of Relativity Put to the Test
Theory of relativity
What is the General Theory of Relativity?
The theory of relativity usually encompasses two interrelated theories by Albert Einstein: special relativity and general relativity. Special relativity applies to elementary particles and their interactions, describing all their physical phenomena except gravity. General relativity explains the law of gravitation and its relation to other forces of nature. It applies to the cosmological and astrophysical realm, including astronomy.