• Empty Sets:- A set which does not contain any element is called empty set or null set.

Denoted By        ɸ, { }

• Singleton Sets:- A set which contain only single element is called Singleton Sets. {2}, {ɸ}, {4}
• Finite Set and Infinite Set:- A set which is empty or consists of a definite no. of elements is called finite set otherwise, the set is called in-finite set.

Finite Set – {1, 2, 3, 4}

Infinite Set – {1, 2, 3,…..}

• Equal Sets:- Two sets A & B are said to be equal if they have exactly the same elements and we write A = B.

eg:- {1, 2, 3, 4} = {43, 1, 2}