Convection currents are movements of fluid caused by differences in temperature and density. When a fluid, like water or air, is heated, it becomes less dense and rises. As it rises, cooler, denser fluid moves in to take its place, creating a circular motion. This process helps distribute heat throughout the fluid. In the Earth's atmosphere, convection currents play a crucial role in weather patterns. Warm air rises, leading to the formation of clouds and precipitation, while cooler air descends. Similarly, in the oceans, convection currents help regulate temperatures and influence oceanic currents and climate.