The force that an electromagnetic field exerts on electrically charged particles. It is one of the four fundamental forces of physics (along with the gravitational force and the strong and weak nuclear forces), and the one responsible for most of the forces we experience in our daily lives. The electromagnetic forces acting between the electrically charged protons and electrons inside atoms and between atoms are essentially responsible for gluing together all ordinary matter. Although hugely stronger (1042 times) than the force of gravity, it is a less dominant force on larger scales because the attractive and repulsive interactions tend to cancel each other out. Like gravity, the electromagnetic force is subject to an inverse-square law, and its strength is inversely proportional to the square of the distance between the particles. The force is mediated or operated by the exchange of photons between the particles. The ‘electrostatic force’ is one aspect of the electromagnetic force, which arises when two charged particles are static (i.e. not in motion).