Cross Section of Blade

Pressure side. Also known as the Windward side. This is the side of the blade faces towards the wind.

Suction side. Also known as the Leeward side.

Leading edge. This is the rounded, front side of the blade that cuts through the air as the blade rotates.

Trailing edge. This is the back edge of the blade. In some parts in can be only 3-4mm thick. Air is released from the trailing edge.