What are easterlies and westerlies?

The Earth contains five major wind zones: polar easterlies, westerlies, horse latitudes, trade winds, and doldrums.

• Easterlies: There are two types of easterlies. They are
• Polar easterlies: They are dry and cold prevailing winds that blow from the east. They emanate from the polar highs, areas of high pressure around the North and South Poles. Polar easterlies flow to low-pressure areas in sub-polar regions.
• Trade winds: They are the powerful prevailing winds that blow from the east across the tropics. Trade winds are also known as tropical easterlies. They start blowing from the sub-tropical high-pressure areas towards the equatorial low-pressure belt. 
• Westerlies: Westerlies are the Permanent winds that blow in the middle latitudes. They blow from the subtropical high-pressure belts towards sub-polar low-pressure belts. The westerlies of the Southern hemisphere are more robust and constant than the westerlies of the Northern hemisphere.

Further Reading:

• Types of Wind
• Geography Notes