The dramatic shift introduced by the theory of relativity in physics is the understanding of the relationship between time and space. This theory, developed by Albert Einstein, revolutionized classical mechanics by establishing that time and space are interconnected and relative, rather than absolute. The theory consists of two parts: special relativity, which addresses the physics of objects moving at constant speeds, and general relativity, which describes the effects of gravity on the curvature of space and time. This groundbreaking perspective reshaped our comprehension of the universe and laid the groundwork for modern physics.