Braille is a tactile (touch-based) system of written language that features patterns of raised dots to represent letters of the alphabet, common words and contractions, mathematical symbols, and punctuation. Named after its developer, Louis Braille, braille allows people who are blind to read and, with adaptive technology, to write. There are a number of braille variations in common use in the US, including braille specific to music, mathematics, science, and computer programming. Learning each of the different forms of braille code is like learning a new language. Therefore, most people only learn the one or two of those they are most likely to use in their daily lives.