The primary force behind ocean currents is the wind, combined with factors like the Earth's rotation (Coriolis effect) and differences in water density. Winds create surface currents by pushing water and transferring energy across the ocean's surface. Additionally, factors such as temperature and salinity gradients contribute to thermohaline circulation, which involves deeper currents. These currents play a vital role in regulating climate, distributing heat, and influencing weather patterns globally, thereby affecting ecosystems and marine life significantly.