The backsplahs is the surface of the wall between the top of the counter and bottom of the upper kitchen cabinets. This is an area people use to decorate their kitchens with unique patterns, colors, and surface types.
The most important feature of the backsplash, though, is that it is stain resistant, as backsplashes are there to protect the wall from cooking splashes and stains. Commonly, ceramic tiles are used as a backsplash, but stainless steel and natural stone have gained popularity recently.