A socket wrench is a tool used to tighten or loosen nuts and bolts. It consists of a handle and a detachable socket that fits over the fastener. The design allows for greater torque, making it easier to work with stubborn or rusted fasteners. Socket wrenches come in various sizes to accommodate different fastener sizes. They are often part of a larger set that includes multiple sockets and extensions, allowing for versatility in various mechanical tasks. Commonly used in automotive repair and construction, they are essential for both professionals and DIY enthusiasts.