A box wrench is a versatile tool that is used to tighten or loosen bolts and nuts. It has two ends, with a tight, square-shaped jaw on each end that grip the bolts or nuts. There are several synonyms for the word "box wrench," including spanner wrench, socket wrench, ratchet wrench, gear wrench, and combination wrench. These tools differ in their design and the type of fastener they can handle. For example, a socket wrench has a hollow cylinder that fits over a nut, while a gear wrench has a ratcheting action for easier turning. Each of these synonyms has its own strengths and weaknesses, but all are useful in their own right for various jobs.