* Mechanical waves require a medium: Mechanical waves, like sound waves, need a medium (like air, water, or a solid) to travel through. They transfer energy by the vibration of particles within that medium.

* Sun rays are electromagnetic radiation: Sun rays are a form of electromagnetic radiation, which are disturbances in electric and magnetic fields that travel through space as waves. They don't need a medium to propagate, and they can travel through a vacuum.

Here's a breakdown of the key differences:

| Feature | Mechanical Wave | Electromagnetic Wave |

|---|---|---|

| Medium Required | Yes | No |

| Energy Transfer | Through particle vibrations | Through oscillating electric and magnetic fields |

| Examples | Sound waves, water waves, seismic waves | Light waves, radio waves, X-rays, microwaves |

So, while sun rays exhibit wave-like properties, they are classified as electromagnetic waves, not mechanical waves.