A hand sander is a tool used to smooth surfaces by sanding them down. It typically consists of a flat base that holds sandpaper and is designed for manual operation. Hand sanders come in various shapes, including rectangular and triangular, to reach different areas and corners effectively. They are commonly used in woodworking, furniture refinishing, and home improvement projects. There are different types of hand sanders, such as the block sander and detail sander. The block sander is ideal for larger, flat surfaces, while the detail sander is perfect for intricate work. Using a hand sander helps achieve a smooth finish before painting or staining surfaces.