Suction cups are simple devices that create a vacuum seal when pressed against a smooth surface. They are typically made of flexible materials like rubber or silicone, allowing them to conform to the surface and hold tightly. When the air is pushed out from underneath, the atmospheric pressure keeps the suction cup in place, making it useful for hanging items or securing objects. These versatile tools are commonly used in various applications, from bathroom accessories like soap dishes to automotive gadgets for holding GPS devices. Suction cups can also be found in scientific experiments and toys, showcasing their practicality in everyday life.