What are Trade Winds? How are they caused?

Trade Winds are the surface winds which move from the Horse Latitudes to the Doldrums. In the Northern Hemisphere, they are the North-East trades and in the Southern Hemisphere, the South-East trades.

The wind always blow from high pressure area towards low pressure area. The trade winds are caused by movement of winds from Sub-Tropical high pressure belts towards equatorial low pressure belt.