Theory of relativity explained to kids

Albert Einstein's theory of relativity is a theory that explains the physical laws that govern how objects move. It is based on the idea that the laws of physics are the same for all observers, regardless of their relative motion. Einstein's theory of relativity has two parts: special relativity and general relativity. Special relativity is the theory that explains the physical laws that govern how objects move when they are moving at a constant speed in a straight line. General relativity is the theory that explains the physical laws that govern how objects move when they are moving at any speed and in any direction. Einstein's theory of relativity has many important applications in physics, including in the fields of astrophysics, cosmology, and quantum mechanics.