g
Symbol  Format  Data 

g  Code Point 
U+0067 
TeX 
g 

SVG 
The Latin letter g is often used in mathematics to represent a function. Typically, the symbol is used in an expression like this: . In plain language, this represents the function which takes in a number as input.
The capital Latin letter G.
A function takes input and produces output. The idea is a useful way to abstract away complexity and, especially in the age of computers, is a practical tool to solve problems.