What are the two types of relativity identified by Einstein?

The two types of relativity identified by Einstein are General Relativity and Special Relativity. Special Relativity, introduced in 1905, focuses on the physics of objects moving at constant speeds, particularly at speeds close to that of light. It fundamentally changed our understanding of time and space, demonstrating that measurements of time and distance are not absolute but are relative to the observer's state of motion.

General Relativity, which was published in 1915, extends these principles to include acceleration and introduces the concept of gravitation as a curvature of spacetime caused by mass. This theory provides a framework for understanding how massive objects influence the geometry of the universe and the motion of objects within it, explaining phenomena such as the bending of light around massive bodies.

The other options presented do not accurately reflect Einstein's contributions. Quantum Relativity is not a recognized type of relativity, and Classical Relativity does not exist as a formal concept within Einstein’s theories. The term "Gravity Theory" is too vague, as gravity is addressed within General Relativity but does not represent a separate category of relativity. Thus, the correct identification of Einstein's work points to General and Special Relativity as the key frameworks for understanding how physics operates differently under varying conditions of speed