Quarter round (also called a base shoe), a term typically used in the flooring industry, is a convex molding that has a cross section in the form of a quarter circle or an ellipse.
Typically used as a flooring joint between the flooring and the baseboard, quarter round is not a requirement for flooring, but in the United States, it is preferred due to its aesthetic appeal. It covers the uneven edge as flooring meets the baseboard.
Often the base shoe (Quarter Round) is molded or shaped into the baseboard itself negating the need for any additional joins.
Quarter round is typically sold in various materials such as natural hardwood, engineered hardwood and laminate.