:The colon symbol ":" is used in mathematics to denote a variety of relations, including ratios, mappings, and divisions. It is often used to express a relationship between two quantities or to define a function or mapping from one set to another.
Ratio between two pairs of numbers, indicating proportionality.
a : b = c : dFunction f is a mapping from set X to set Y.
f: X \to YDivision or ratio of x to y.
x : y