In Java, collections are used to store and manipulate groups of objects. There are several types of collections in Java, including:
List: A List is an ordered collection of elements that can contain duplicates. It allows access to its elements using an index, and elements can be added or removed from any position in the list.
Set: A Set is a collection of elements that do not allow duplicates. It is an unordered collection and does not provide access to its elements using an index.
Map: A Map is a collection of key-value pairs, where each key is associated with a value. It does not allow duplicate keys and provides methods for accessing and modifying the values associated with a particular key.
Queue: A Queue is a collection that orders its elements in a specific way, such as first-in-first-out (FIFO) or last-in-first-out (LIFO). It provides methods for adding, removing, and retrieving elements from the collection.
Deque: A Deque (Double-ended queue) is a type of Queue that allows elements to be added and removed from both ends of the collection.
Vector: A Vector is a dynamic array that can grow or shrink as needed. It is similar to an ArrayList but is synchronized, which makes it thread-safe.
Stack: A Stack is a collection that orders its elements in a last-in-first-out (LIFO) manner. It provides methods for adding, removing, and retrieving elements from the collection.