Which tool is primarily used for buffing the nail surface?

The nail buffer is specifically designed for buffing the nail surface, making it the ideal tool for this purpose. Buffers typically have a smooth, cushioned texture that gently polishes the nail plate to achieve a shiny finish and smooth out any imperfections. This tool can be used to enhance the natural shine of the nails or prepare them for nail polish application, creating an even base.

While the file is used primarily for shaping the edges of the nails, the cuticle pusher is intended for pushing back the cuticles, and the nail brush is used for cleaning the nails and removing debris. Each of these tools has distinct functions that do not include buffing the nail surface, which is why the nail buffer stands out as the correct choice for this specific task.