Braille uses cells of six raised dots , in two columns of three dots .
For example , dots 1-3-4 ( â ) would describe a cell with three dots raised , at the top and bottom in the left column and on top of the right column , i.e. , the letter m. The lines of horizontal Braille text are separated by a space , much like visible printed text , so that the dots of one line can be differentiated from the Braille text above and below .