A ratchet wrench is a type of hand tool used for tightening or loosening fasteners, such as nuts and bolts. It features a mechanism that allows the user to turn the tool in one direction while the socket remains engaged with the fastener, making it efficient for repetitive tasks. This design helps save time and effort, especially in tight spaces. Ratchet wrenches come in various sizes and styles, including socket wrenches and combination wrenches. They are commonly used in automotive repair, construction, and maintenance tasks. The versatility and ease of use make ratchet wrenches a popular choice among both professionals and DIY enthusiasts.