What are currents? What causes these currents?

Ocean current is the general movement of a mass of oceanic water in a definite direction, which is more or less similar to water streams (rivers) flowing on the land surface of the Earth.

The currents are produced by interaction of various factors. These are:

1. Planetary winds
2. Variation in sea water temperature
3. Variation in sea water salinity
4. Rotation of the earth
5. Configuration of Coastlines