The theory of sets was developed by German mathematician Georg Cantor (1845-1918).
A set is a collection of well-defined objects.
There are two methods of representing a set:
(i) Roster or tabular form.
(ii) Set-builder form.
Example of Sets:
(a) The rivers of India.
(b) The vowels in the English alphabet.
(c) The set of all natural numbers.
(i) Roster form
(ii) Set-builder form: