Aircraft
In aircraft, blade pitch is usually described as "coarse" for a high angle of attack, and "fine" for a low angle of attack.
Blade pitch is normally described in units of distance/rotation assuming no slip.
Blade pitch acts much like the gearing of the final drive of a car. Low pitch yields good low speed acceleration (and climb rate in an aircraft) while high pitch optimizes high speed performance and economy.
Because the velocity of a propeller blade varies from the hub to the tip, they must be of twisted form in order for the pitch to remain constant along the length of the blade. This is typical of all but the crudest propellers.
It is quite common in aircraft for the propeller to be designed to vary pitch in flight, optimizing both cruise and takeoff performance.
Read more about this topic: Blade Pitch