The latin letter n is commonly used in math as a variable.
A variable is a core concept in algebra where a symbol, usualy a lower case latin letter, is used as a placeholder in a math expression.
The Latin Alphabet is a collection of 26 symbols that form the basis of the English language. The alphabet's symbols are used throughout mathematics to represent variables, constants, and coeffecients.
The capital Latin letter N is used in mathematics to represent the set of natural numbers. Usually, the letter is presented with a "double-struck" typeface to indicate that it is the set of natural numbers. Otherwise, N is also used as a variable.