Alphabet

An alphabet is a finite nonempty set of symbols. An alphabet for a particular language consists of the characters which make up the words of said language. Alphabets form one of the pillars of formal language analysis, aiding in the calculation of Kolmogorov complexity, among other things.

Binary
0 1

English
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

Brainfuck
+ - > <, . [ ]