We observe World Braille Day on 4 January every year to spread awareness about braille as an important means of communication for people with visual disabilities. Unlike English, Hindi, Spanish, etc., braille is not a language. Instead, it is a code that helps people with visual difficulties read. 

1. Braille consists of a code made up of 63 characters.
2. A braille cell has six dots arranged in two columns and three rows. Each dot is numbered in the order mentioned below: 

                               1                4   

                               2               5 

                               3               6 

3. English letters A to J are formed using dots 1, 2, 4 and 5. 

4. English letters K to T are written by adding dot number 3 to each character in letters A to J.

5. English letters U, V, X, Y and Z are written by adding dot number 6 to each character in letters K to T.
6. W was skipped because it did not exist in French when Louise Braille, who was French, invented this code. Later, it was created using dots 2, 4, 5 and 6.

7. These are all the lowercase braille letters in the English alphabet. To form a capital letter, you must place a dot 6 before the letter.

Sources: 

Braille | History, Inventor, Description, & Facts | Britannica 

Braille – Wikipedia 

How the braille alphabet works – Perkins School for the Blind