How object is storing other objects

Question

Below is a Linked List class which is storing other nodes, I want to know in function AddLast how head object is storing all other objects because when I call PrintNodes method then it print all the nodes in this order First, second and third, but I'm not getting how head is storing these objects, I want to know memory structure

    public class Node

    {

        public Object data;

        public Node next;

        public Node(object data)

        {

            this.data = data;

        }       

    }

    public class LinkedList

    {

        private Node head;

        private Node current;

        public void Add(Node nodeToAdd)

        {

            nodeToAdd.next = head;

            head = nodeToAdd;

        }

        public void AddLast(Node nodeToAdd)

        {

            if (head == null)

            {

                head = nodeToAdd;

                current = head;

            }

            else

            {

                current.next = nodeToAdd;

                current = current.next;

            }

        }

        public void PrintNodes()

        {

            while (head != null)

            {

                Console.WriteLine(head.data);

                head = head.next;

            }

        }

static void Main(string[] args)

        {

            LinkedList l = new LinkedList();

            //l.Add(new Node("first"));

            //l.Add(new Node("second"));

            l.AddLast(new Node("first"));

            l.AddLast(new Node("second"));

            l.AddLast(new Node("third"));

            l.PrintNodes();

          

            Console.ReadKey();

        }