In which type of Collection are duplicate values not allowed?

A set is a type of collection that restricts the existence of duplicate values. A set is a collection that depicts a collection of elements but forbids duplications.

A set is a data structure that stores elements in an unordered manner and is used in computer languages like Java, Python, and C#. The data structure determines whether an element already exists in a Set before adding it. The element is ignored if it is not present; otherwise, it is added to the Set.

Operations like union, intersection, and difference of two sets can be carried out using sets. When the uniqueness of elements is crucial, sets can be used to count unique items in a list, determine whether two lists share any elements, or eliminate duplicates.

In conclusion, sets are collections that prevent the occurrence of duplicate values and are helpful for activities where each element must be unique.