A fundamental force in nature, the electromagnetic force acts between charged particles and is the combination of all electrical and magnetic forces. The electromagnetic force can be attractive or repulsive. It has infinite range, although its strength is inversely proportional to the inverse square of the distance (that is, doubling the distance between two charged particles decreases the force between them by a factor of four). Aside from gravity, the electromagnetic force is responsible for all forces we experience directly (the only other two known fundamental forces are the "strong force" and the "weak force," which hold together the particles in the nucleus of an atom). For example, the electromagnetic force holds atoms together in molecules, causes friction, and attracts iron to a magnet.
Electromagnetic (EM) radiation is a form of energy that is all around us and takes many forms, such as radio waves, microwaves, X-rays and gamma rays. Sunlight is also a form of EM energy, but visible light is only a small portion of the EM spectrum, which contains a broad range of electromagnetic wavelengths.