How is the data structure used in linked lists implemented?

A linked list is implemented as a sequence of nodes, where each node contains data and a reference to the next node (in a singly linked list) or to both the next and previous nodes (in a doubly linked list).

Example of a singly linked list node structure in Java:

class Node {
    int data;
    Node next;

    Node(int data) {
        this.data = data;
        this.next = null;
    }
}

A linked list stores a reference to the first (head) node. To add, delete, or search for elements, traversal is performed by following links from one node to another.

This structure allows efficient insertion and deletion of elements in the middle of the list, but access by index is slower than in arrays.