A scissor jack is a mechanical device used to lift heavy objects, commonly found in automotive applications. It operates using a scissor-like mechanism that expands and contracts, allowing for vertical lifting. When the handle is turned, the arms of the jack move apart, raising the platform at the top. Scissor jacks are typically compact and lightweight, making them easy to store in vehicles. They are often used to change tires or perform maintenance on cars. Safety is important when using a scissor jack, as improper use can lead to accidents or injuries.