Now, mechanical waves are of two types - transverse waves and longitudinal waves.

Transverse waves, where the particles of the medium vibrate in a direction

perpendicular to the direction of wave propagation. This produces

interference. (example - interference in water ripples)

Longitudinal waves, where the particles of the medium vibrate in a direction

parallel to the direction of wave propagation. This produces interference.

(example is sound waves)

Similarly, non - mechanical waves like electromagnetic waves and light also

produce interference patterns.

Hence, phenomenon of interference is shown by both mechanical and non - mechanical waves.