What is the primary role of a sander in woodworking?

The primary role of a sander in woodworking is to smooth surfaces and prepare them for finishing. Sanding is a crucial step in the woodworking process because it helps to remove rough spots, imperfections, and old finishes, resulting in a surface that is ready for treatments such as staining or sealing. A properly sanded surface enhances the appearance and durability of the final product, allowing finishes to adhere properly and providing a professional look.

In contrast, joining pieces of wood involves techniques like gluing or using mechanical fasteners, which is not the main function of a sander. Cutting wood into specific shapes requires tools like saws, which are designed for removing material rather than smoothing it. Measuring and marking wood is a foundational step in woodworking that involves accuracy and planning, but it does not relate to the action of sanding. Thus, the focus of a sander is specifically on surface preparation, making the associated answer the most accurate.