Current

Current is a term with multiple closely related meanings across science and everyday language. In physics, electric current refers to the rate at which electric charge flows through a conductor. It is measured in amperes (A) and can be described as conventional current, which assumes positive charge flow, or electron flow, which is actual negative charge movement. Electric current can be direct (DC), where charge moves in a constant direction, or alternating (AC), where the direction reverses periodically. Ohm’s law relates current to voltage and resistance (I = V/R), and circuits describe how sources, conductors, and components interact to control current.

In fluid dynamics, a current denotes the horizontal movement of a fluid, such as water or air. Water currents occur in rivers, oceans, and coastal systems, while air currents refer to winds and jet streams. Currents are characterized by speed and direction and are influenced by gravity, density differences, and external forces like wind and tides. They play a critical role in shaping climate, weather, and marine ecosystems, and they are measured with instruments such as flow meters and current profilers.

In everyday usage, current often describes things that are happening now or are up to date, as in current events or current fashions. The adjective indicates immediacy or contemporaneity, and it is commonly used in contexts ranging from news to technology to organizational status.

Etymology-wise, the word current derives from Old French courant, itself from Latin currens, meaning running or flowing. The term has been adopted across disciplines to signify a flow or progression in time or space.