What are the 2 assumptions that the Theory of Relativity makes?

The Theory of Relativity is based on two key assumptions: first, the laws of physics are the same for all observers, regardless of their relative motion, which is known as the principle of relativity; second, the speed of light in a vacuum is constant and does not vary, regardless of the motion of the light source or observer. These assumptions lead to profound implications for our understanding of space, time, and gravity.