A tonneau cover is a protective cover designed for the open bed of a pickup truck. It helps shield cargo from weather elements like rain and snow, while also providing security against theft. Tonneau covers come in various styles, including hard and soft options, allowing truck owners to choose based on their needs. In addition to protection, a tonneau cover can improve a truck's aerodynamics, potentially enhancing fuel efficiency. Many covers are easy to install and remove, making them a practical choice for those who frequently use their truck bed for different purposes.