A B C D E F G H I J K L M N O P Q R S T U V W X Y Z
Letters are the marks and the sounds which make up words. There are twenty-six letters in the English alphabet. The ones typed above are the capital or the upper-case letters. The ones typed below are the small or lower-case letters.
a b c d e f g h i j k l m n o p q r s t u v w x y z
A letter, on the other hand, can also be a piece of correspondence. This kind of letter contains some number of words. And each word is made up of one or more letters.
Which means a letter (singular) is made up of many letters!!!