Light energy refers to the energy carried by waves in the visible region of the electromagnetic (EM) spectrum. The EM spectrum is comprised of the entire range of electromagnetic radiation from radio waves all they way up to gamma rays.
All traveling waves carry energy, whether they are ocean waves, sound waves, light waves or radio waves. Waves carry energy by wave motion, which transfers energy from point to point, often without displacing matter, at least not permanently. Electromagnetic radiation is a form of radiant energy. It is formed when energy absorbed by an atom causes an electron to change its location. When that electron falls back into its original configuration, an electromagnetic wave is produced. EM waves occur along a wide range of frequencies and wavelengths, all the way from gamma rays with wavelengths that are only a trillionth of a meter in length, to extremely low frequency radio waves with wavelengths that can be 100,000 kilometers long. Only a small part of the EM spectrum is visible. The energy from light waves can be used to power solar generators. It is also used by plants to power the process of photosynthesis. All types of electromagnetic radiation travel at a constant speed, the speed of light.