What does the set() function return when provided with a list?

The set() function converts the provided list into a set, which is a data structure that holds an unordered collection of unique elements. When a list containing duplicates is passed to the set() function, it will return a new set that contains only one of each unique element from the list, effectively removing any duplicate entries. This is a fundamental property of sets in Python, where each element must be unique.

Using set() is a common way to filter out duplicates from a list, making it particularly useful for operations where the uniqueness of elements is required, such as in membership tests or when maintaining collections of distinct items. By converting a list to a set, developers take advantage of set operations and properties, benefiting from faster membership checking and the ability to perform mathematical set operations like unions and intersections.