Light waves travel from the sun to our eyes or from lights.
Without light there wouldn't be parks or plants. Humans would be able to live.
Light travels 299,792,459 m/s. That's fast enough to go around the earth 7.5 times in a second.
Light is an electromagnetic wave. That means that it can travel through a vacuum. It can also travel through a medium it just slows down every so slightly.
There are many lights in the electromagnetic spectrum. If you are wearing a green shirt, that means that the green is being reflected by the shirt while the other colors are absorbing it.
Light waves have a lot of energy so that means a bigger frequency. If light waves didn't have so much energy, then the amplitude would be less. Now if the frequency was bigger, then the wavelength would be shorter. If the frequency was lower, the wavelength would be longer.