Doubly Linked List

Doubly Linked List-A more sophisticated kind of linked list is a doubly-linked list or two-way linked list. Each node has two links: one points to the previous node, or points to a null value or empty list if it is the first node; and one points to the next, or points to a null value or empty list if it is the final node.

Illustration:

Reference:

http://en.wikipedia.org/wiki/Linked_list#Doubly-linked_lists