Braille is a system by which blind people are able to read. The system is composed of the basic alphabet plus numerous contractions and short cuts.
There are 3 grades of braille. Grade 1 has no contractions. Grade 2 has about 200 contractions. Grade 3 has about 700 contractions. Most people rea grade 2.
A braille cell is composed of 6 dots. Imagine the cell as a verticle rectangle. Dots 1,2,3 are on the left hand side of the cell. Dots 4,5 and 6 are on the right side. The letters of the alphabet are a combination of dots within this cell. For example, the letter A is dot 1. The letter C is dots 1 and 4.
I mentioned contractions before. Contractions are used because they take up less space and allow for faster reading. An example of a contraction is dots 5,6 and the letter N. This combination stands for the letters TION.
For more information contact the National Federation of the Blind and the American Foundation for the Blind.