A Braille character consists of up to six dots, numbered top to bottom, left to right, in two columns of three.  The dot pattern look like this:

                                          1  4
                            2  5
                            3  6

Braille is intended to be “printed” on heavy stock paper, with each dot in each character raised above the page; it is “read” by running your index finger across the raised dots.  It is also possible to read Braille by sight, which is all this program will be able to teach you.  (Brailler’s custom-made Braille font approximates the size of actual raised Braille characters, so this should not be a difficult transition.)