A router jig is a tool used in woodworking to guide a router for precise cuts and shapes. It helps ensure accuracy and consistency when creating joints, inlays, or decorative edges. By providing a stable framework, a router jig allows woodworkers to achieve professional-quality results with ease. These jigs can be custom-made or purchased, and they come in various designs to accommodate different tasks. Some common types include mortise jigs, dovetail jigs, and template jigs. Using a router jig can significantly enhance the efficiency and quality of woodworking projects.