Wainscoting consists of short boards which are attached to the bottom part of a wall. They are attached vertically and run along the perimiter of a room. Wainscoting is often installed to protect parts of the wall where drywall may get dented.
Some of the earliest buildings in North America were built with wainscoting, which can also be a decorative choice and not just for wall protection. The boards are usually made of finished wood or vinyl. If you need to protect that always problematic bottom wall area of your home, I'd suggest perusing the following site for DIY installation instructions.