Rudders are essential components used in various types of vehicles, particularly in boats and ships. They are typically flat, vertical surfaces located at the stern (back) of the vessel. When the vessel moves through water, the rudder can be turned to create a force that changes the direction of the boat, allowing for steering and navigation. In addition to marine vessels, rudders are also found in aircraft, where they help control yaw, or side-to-side movement. Similar to steering wheels in cars, rudders enable precise control, making them crucial for safe and effective travel across water and air.