Diffraction

Yes, it strongly depends on the wavelength of the light wave. It is directly proportional to the length i.e. longer the wavelength, more will be the amount of diffraction. Similarly, short wavelength of the light will mean less diffraction comparatively.

Reflection is the concept of bouncing back of light waves when passed through a surface. Whereas, diffraction is a term used when light waves spread in different directions on being passed through an obstacle. Reflection requires a smooth surface whereas diffraction requires the edge of an object.

Interference is a concept that forms the base of diffraction, without which diffraction is not practically possible. The waves formed by diffraction form secondary waves which either cross each other, move in directions opposite to each other, or overlap each other. This situation creates some alternating bright and dark fringes called interference.