Albert Einstein is known for which groundbreaking theory?

Albert Einstein is renowned for developing the Theory of Relativity, which fundamentally changed the way we understand space, time, and gravity. This theory is primarily divided into two parts: special relativity and general relativity. Special relativity, introduced in 1905, revolutionized the understanding of how time and space are intertwined and how they relate to the speed of light. General relativity, introduced in 1915, expanded on this by incorporating gravity into the framework, proposing that gravity is not just a force but a curvature of space-time caused by mass. This was a radical shift from Newtonian mechanics, which treated gravity as a force acting at a distance.

The other theories mentioned in the question—such as the Theory of Evolution, which explains biological changes over time through natural selection; the Theory of Quantum Mechanics, which describes the behaviors of particles at the atomic and subatomic levels; and the Theory of Gravity, often associated with Newton, who formulated a universal law describing gravitational attraction—are significant in their own right but do not pertain to Einstein's most notable contributions. His work on relativity has had a lasting impact across multiple fields, including physics, astronomy, and even philosophy, making it a cornerstone of modern scientific understanding.