This document defines and provides examples of different types of sets: empty sets, singleton sets, finite and infinite sets, union of sets, intersection of sets, difference of sets, subset of a set, disjoint sets, and equality of two sets. Empty sets have no elements. Singleton sets contain one element. Finite sets have a predetermined number of elements while infinite sets may be countable or uncountable. The union of sets contains all elements that are in either set. The intersection contains elements common to both sets. The difference contains elements in the first set that are not in the second. A set is a subset if all its elements are also in another set. Sets are disjoint if their intersection is empty. Two sets are equal