The Double-Slit Experiment is a famous physics experiment that demonstrates the fundamental principles of quantum mechanics. When particles like electrons are fired at a barrier with two slits, they create an interference pattern on a screen behind the barrier, suggesting that they behave like waves. This phenomenon challenges our classical understanding of particles and waves. However, when the particles are observed or measured as they pass through the slits, they behave like individual particles, and the interference pattern disappears. This intriguing result highlights the role of observation in quantum mechanics and raises questions about the nature of reality itself.