How does buffing metal make it shiny and reflective?

Buffing, usually done once the polishing has been completed. Polishing refers to using an abrasive that is adhered to a wheel, paper or cloth. Polishing normally starts with a coarse grit and works up to a fine grit. Buffing continues where polishing ends. Buffing refers to using an abrasive that is added to a wheel or cloth. Polish is a very fine grit abrasive, think pumice and the like. The abrasive material is usually held in a suspension of wax or a liquid.

Polishing starts by removing any impurities on the surface, any nicks or blemishes. As the grit used gets finer it removes any scratches left by the previous abrasive. Right up to the grits in the 1000’s that finish the buffing process.