Usually, a linked list internally has a structure that stores two or three references: that to the data stored, that to the successor (next node) and optionally that to the previous node.
That's exactly how java.util.LinkedList have done it, with one major difference. While most linked lists are actually that - linked lists, i.e. a chain of nodes, java.util.LinkedList uses a chain structure. It has a special node that connects the first and last node together. Please note that this is mostly for performance issues, because you can now go both ways when traversing the list, choosing the shortest path to any node.