A buoy is a floating device used in water to mark locations, provide information, or aid navigation. They are often brightly colored and can be found in oceans, lakes, and rivers. Buoys help sailors and boaters know where they are, warn them of hazards, or indicate safe areas for swimming. There are different types of buoys, such as navigation buoys, which guide ships through channels, and moorings, which allow boats to anchor safely. Some buoys even have lights or sounds to make them more visible, especially at night or in foggy conditions, ensuring safety for everyone on the water.