Volta, often referred to as the volt, is the unit of electric potential in the International System of Units (SI). It measures the potential difference that drives electric current through a circuit. One volt is defined as the potential difference that will move one ampere of current against one ohm of resistance. The term is named after the Italian physicist Alessandro Volta, who invented the first chemical battery, known as the Voltaic pile, in the early 1800s. This invention was crucial in the study of electricity and laid the groundwork for modern electrical engineering.