Wind-driven currents affect about 20% of the ocean's total volume. These are the only currents that most people see. Sailors have charted patterns of the ocean's currents for hundreds of years. TOPEX/Poseidon is the first space mission that allows scientists to use ocean topography to calculate the speed and directions of ocean currents almost everywhere in the ocean.
The sun ultimately creates winds in the atmosphere and ocean currents. Because the equator receives more direct rays from the sun throughout the year, the equatorial oceans " heat up " more than the oceans at higher latitudes in both the north and the south. This creates a temperature imbalance, which creates a pole ward flow of heat by way of the atmospheric winds and the oceanic currents. Unequal heating of the atmosphere on land and the oceans creates winds and circulation.
Here's an important distinction! Wind direction indicates the direction the wind originates from. For example, a " north wind " blows out of the north to the south. This is the opposite of water-current flow. A " northerly current " flows to the north, not out of the north. It's important to keep this distinction in mind when learning about wind and ocean currents.