Braille is a reading and writing system used by visually impaired people.
The letters of the alphabet and the numbers are formed from different combinations of a set of six dots arranged in two vertical rows of three, like a domino. A visually impaired person can interpret these dots when moving a finger along a line of Braille. The English inventor, Dr William Moon devised the code named after him in 1847. It was one of the most popular of a range of tactile codes used in this country until the 1880's when Braille took over. Moon is a line based tactile code in which many of the letters are simplified versions of the printed alphabet.