List is an Ordered Collection while Set is an unordered Collection.

List maintains insertion order of elements, means any element which is inserted before will go on lower index than any element which is inserted after.

Set in Java doesn’t maintain any order.

## Is set in python ordered?

Set in Python is a data structure equivalent to sets in mathematics. It may consist of various elements; the order of elements in a set is undefined.

## Is HashSet ordered?

HashSet in Java. The HashSet class implements the Set interface, backed by a hash table which is actually a HashMap instance. No guarantee is made as to the iteration order of the set which means that the class does not guarantee the constant order of elements over time. Objects are inserted based on their hash code.

## Do sets maintain order?

A Set will not allow duplicate values. And LinkedHashSet will preserve insertion order. Hash table and linked list implementation of the Set interface, with predictable iteration order. This linked list defines the iteration ordering, which is the order in which elements were inserted into the set (insertion-order).

## What does it mean for a set to be well ordered?

In mathematics, a well-order (or well-ordering or well-order relation) on a set S is a total order on S with the property that every non-empty subset of S has a least element in this ordering. The set S together with the well-order relation is then called a well-ordered set.