Question

What property separates light waves from all other waves? Is all light visible to humans? Please answer all parts of the question completely and fully.

Answer 1

Light waves are electromagnetic waves. Electromagnetic waves are waves which means that they are disturbances in a particular physical medium and result in oscillations, but they differ from all other waves because they consist of 2 waves oscillating perpendicular to each other.One of these waves is an oscillating magnetic field and the other is electric. 
Electromagnetic waves are characterized with their wavelength (lambda).
No all electromagnetic waves are visible to humans. The visible spectrum is the light that we can see with our eyes is only a small fraction from the whole spectrum.