Braille is a tactile writing system used by blind and visually impaired people. It consists of patterns of dots that can be felt with the fingers. Each Braille cell is made of 6 dots arranged in 2 columns of 3 dots each. Patterns of raised dots represent letters, numbers, and punctuation. Braille allows blind people independent access to reading and writing as well as computers and mobile devices through refreshable Braille displays and screen readers. While originally developed for the blind, Braille has evolved to represent many languages and technical symbols.