Two sets are equal if and only if they have precisely the same elements. A Set is a collection of things usually numbers. C denotes the set of all complex numbers.
Some notations for sets are.
C denotes the set of all complex numbers. In set theory and its applications to logic mathematics and computer science set-builder notation is a mathematical notation for describing a set by enumerating its elements or stating the properties that its members must satisfy. Natural numbers are whole counting numbers. In short the set formed by the negative integers the number zero and the positive integers or natural numbers is called the set of integers.