Difference between CR LF, LF and CR line break types CR and LF are control characters, respectively coded 0x0D (13 decimal) and 0x0A (10 decimal) They are used to mark a line break in a text file As you indicated, Windows uses two characters the CR LF sequence; Unix (and macOS starting with Mac OS X 10 0) only uses LF; and the classic Mac OS (before 10 0) used CR An apocryphal historical perspective: As indicated by Peter, CR = Carriage