Propeller pitch refers to the angle of the blades on a propeller, which affects how much air or water the propeller moves with each rotation. A higher pitch means the blades are angled more steeply, allowing the propeller to push more fluid but requiring more power. Conversely, a lower pitch allows for easier rotation and less power needed, but moves less fluid per turn. In aviation, the pitch of a propeller is crucial for performance. It influences speed, fuel efficiency, and the ability to climb. Adjusting the pitch can optimize a plane's performance for different flight conditions, such as takeoff or cruising.