In mathematics, a set is a collection of distinct elements. Note that a set can be considered an element in its own right. The elements in a set may be anything: numbers, people, letters of the alphabet, other sets, and so on. Conventionally, sets are symbolized by capital letters.
In order for us to attain a clearer understanding of sets, we may look at some basic examples:
Suppose A is the set of the first four positive even integers.
Suppose B is the set of colors of the American flag.
Hence, A={2,4,6,8}
B={red, white, blue}
Note that these sets are finite.
The key relation between...