Braille is a reading system for people with visual impairments, which was invented in 1821 by the French educator and inventor, Louis Braille. Being born blind in both eyes, Louis Braille discovered a method of using raised dots and letters, to express words and letters to people who were unable to see. Due to the successful nature of Braille, the system has not changed at all since its inception.
Common places you can find braille include: ATMs, pedestrian stopping areas and crossings, and signage.