What term describes a large stream of moving water that flows through the oceans?

The term that describes a large stream of moving water that flows through the oceans is "current." Ocean currents are significant because they influence various aspects of marine and coastal environments, including climate regulation, nutrient distribution, and navigation. These currents can vary in scale, from small, local currents to massive systems like the Gulf Stream, which moves warm water across the Atlantic Ocean.

Understanding ocean currents is critical in oceanography, as they play a major role in heat distribution across the planet and affect marine ecosystems. In contrast, waves refer to the surface movement of water caused by wind and other factors, tides are periodic rises and falls in sea level caused by the gravitational pull of the moon and sun, and flow may refer to the general movement of water but is not a specific term used to describe the structured movement of ocean water like currents are.