A backyard barrier is an object or structure that is used to separate a backyard from the outside environment. The two most common backyard barriers are fences and hedges. A FENCE is a structure made of wood, metal, or other material that is erected around a yard to provide privacy and security. A HEDGE is a line of shrubs or trees planted close together to form a barrier or boundary. Both fences and hedges can be used to create a backyard barrier.