The phenomenon of interference occurs when waves interact with each other, resulting in constructive or destructive interference patterns. When light passes through two parallel slits (known as the double-slit experiment), it exhibits interference patterns due to its wave-like nature.
In the case of light, interference occurs because it behaves as an electromagnetic wave, and when passing through the double slits, the waves from each slit overlap and interfere with each other. This interference creates regions of constructive interference (where waves reinforce each other, resulting in bright fringes) and regions of destructive interference (where waves cancel each other out, resulting in dark fringes). This pattern of light and dark fringes is characteristic of wave interference.
On the other hand, electrons can also exhibit wave-like behavior, as described by quantum mechanics. In experiments similar to the double-slit experiment, electrons have been observed to exhibit interference patterns as well. This demonstrates the wave-particle duality of electrons. However, the key difference is that the interference patterns for electrons are not due to interactions with other electron waves. Instead, the interference arises from the interaction of the electron's wavefunction with itself as it passes through the two slits. This self-interference pattern is a fundamental aspect of quantum mechanics and is not dependent on interactions between separate electron waves.
In summary, while both light and electrons can exhibit interference patterns, the mechanism behind the interference differs. Light exhibits interference due to the interaction of separate light waves, while electrons exhibit interference due to the wave-like behavior of their quantum wavefunctions.