Double-Slit Experiment:An experimental setup where particles pass through two slits and create an interference pattern on a screen, demonstrating both wave-like and particle-like behaviors.
de Broglie Wavelength: $\lambda = \frac{h}{p}$, where $\lambda$ is the wavelength associated with a moving particle, $h$ is Planck's constant, and $p$ is the particle's momentum.
Complementarity: A principle introduced by Niels Bohr stating that physical systems possess complementary properties which cannot be observed or measured simultaneously.