Question

What is one way that light differs from sound?

Answer 1

I'm guessing you're talking about light and sound waves.
Sound waves require a medium, they are longitudinal waves consisting of rarefactions. They also have different kinds of frequencies. Travel at 340 m/s.
Light waves are electromagnetic waves, which travel at 3x10^8 m/s.

There's more but I think that's a good start.

Answer 2

You may also want to mention the particle/wave duality of light, whereas sound only propagates as a wave.