What is the difference between Set and List?

In Java, a Set is an interface that extends the Collection interface. It is an unordered collection of objects, in which each object can occur only once. A Set does not allow duplicate elements.

A List is an interface that extends the Collection interface. It is an ordered collection of elements, in which each element has a specific position in the list. A List allows duplicate elements.

Here are some key differences between Set and List:

• Order: Set is an unordered collection, while List is an ordered collection.
• Duplicates: Set does not allow duplicate elements, while List allows duplicate elements.
• Indexing: List has a specific index for each element, while Set does not have a specific index for its elements.

There are several implementations of the Set and List interfaces in the Java Collections Framework, including HashSet, TreeSet, ArrayList, and LinkedList. You can choose the implementation that is most appropriate for your use case based on your requirements for order, duplicates, and performance.