Albert Einstein, renowned for his theory of relativity, also played a crucial role in the interpretation of quantum mechanics, particularly through his involvement with the double-slit experiment. Although widely known for relativity, Einstein was awarded the 1921 Nobel Prize in Physics for his hypothesis on the photoelectric effect, which suggested that light has particle-like properties, significantly contributing to the development of quantum mechanics. The double-slit experiment, a fundamental demonstration of quantum mechanics, reveals that particles like electrons and photons create an interference pattern when passing through two slits, behaving like waves. However, when an attempt is made to observe which slit the particle passes through, the interference pattern disappears, indicating particle-like behavior. Einstein raised doubts about the probabilistic interpretation of quantum mechanics, advocating for a more deterministic explanation. This led to the famous Einstein-Bohr debates, where Niels Bohr argued that any measurement to determine the particle's path would introduce uncertainty, thus eliminating the interference pattern, based on the uncertainty and complementarity principles. Modern understanding recognizes the double-slit experiment as a key example of wave-particle duality, where particles exhibit wave-like properties until observed, at which point they behave like particles. This experiment also illustrates the concept of wave function collapse upon observation, which is fundamental to the operation of quantum computers. Einstein's critiques have deepened discussions on quantum mechanics, guiding research into its foundational principles for decades.