A set is a well defined list or collection of objects, symbols or 'things , ' called the elements or members of a set. An example of a set { 1 , 2, 3 } Description - this is a set of the first 3 natural numbers. Example 2 { 2, 4 ,6,8 } Description - this is a set of even numbers between 0 and 9 Example 3 { April, June, September, November } Description - this is a set of the months of the year which are 30 days long.