Set (mathematics)

Collection of mathematical objects

In mathematics, a set is a collection of different things; the things are called elements or members of the set and are typically mathematical objects: numbers, symbols, points in space, lines, other geometric shapes, variables, functions, or even other sets. Sets cannot be mathematically defined, since they form a primitive notion. Instead, they are characterized by basic properties (axioms) that sets must have to correspond to intuition about collections.

From Wikipedia, under CC BY-SA. More on occurri.