Braille
Each symbol is coded with certain dots present, and others absent. The dots are approximately 0.02 inches (0.5 mm) high; inside the cell, the dots are about 0.1 inches (2.5 mm) apart. The space between the dots of two cells is about 0.15 inches (3.75 mm) horizontally and 0.2 inches (5 mm) vertically. A standard braille page is 11 inches by 11 inches and typically has between forty and forty-two braille cells per line and twenty-five lines.