The document describes different types of electromagnetic waves categorized by their wavelength. It discusses gamma rays, x-rays, ultraviolet rays, visible light (including the colors green through red), infrared rays, radio waves, microwaves, and their typical wavelengths and properties. Visible light has the longest wavelengths that humans can see between 400-750 nm, while gamma rays have the shortest at 0.0001 nm and carry the most energy.