Final answer:
Diffraction signifies the wave behavior of light, resulting in spreading patterns even through parallel beams and permitting light to travel through curved paths via total internal reflection. When light passes through different mediums, its frequency remains constant. Interference affects the wavelength and direction of light waves.
Step-by-step explanation:
Understanding Diffraction and Behavior of Light
The behavior of light indicated by diffraction is wave behavior. Diffraction occurs when light interacts with small objects or openings, causing it to spread out and create patterns that are indicative of its wave-like properties. This spreading out of light, even when a beam has parallel rays, is inevitable due to the effect of diffraction which is also the reason light and images can travel through a tube that is not straight, this is due to the process of total internal reflection of light.
In the context of light passing from one medium to another, such as air into water, certain properties of the light wave are altered. Specifically, when a monochromatic beam of light enters a different medium, its frequency remains unchanged despite changes in speed and wavelength due to refraction.
When two or more light waves intersect, they superimpose, affecting parameters such as wavelength and direction, known as interference, which can lead to patterns often seen in thin film reflections and other phenomena.