A coulomb is a unit of electric charge in the International System of Units (SI). It is defined as the amount of charge transported by a constant current of one ampere in one second. The symbol for coulomb is C. This unit helps quantify electric charge, which is essential in understanding electrical phenomena. The concept of coulomb is named after the French physicist Charles-Augustin de Coulomb, who studied electrostatics and magnetism in the 18th century. His work laid the foundation for the laws governing electric forces, such as Coulomb's Law, which describes the force between two charged objects.