Linked lists are a way to store data with structures so that the programmer can automatically create a new place to store data whenever necessary. Specifically, the programmer writes a struct definition that contains variables holding information about something and that has a pointer to a struct of its same type . Each of these individual structs or classes in the list is commonly known as a node or element of the list.
One way to visualize a linked list is as though it were a train. The programmer always stores the first node of the list in a pointer he won't lose access to. This would be the engine of the train. The pointer itself is the connector between cars of the train. Every time the train adds a car, it uses the connectors to add a new car. This is like a programmer using malloc to create a pointer to a new struct.
It is necessary to understand how to traverse (go through) the linked list before it really becomes useful. This will allow us to store some data in the list and later find it without knowing exactly where it is located.
Think back to the train. Let's imagine a conductor who can only enter the train through the first car and can walk through the train down the line as long as the connector connects to another car. This is how the program will traverse the linked list. The conductor will be a pointer to node, and it will first point to root, and then, if the root's pointer to the next node is pointing to something, the "conductor" (not a technical term) will be set to point to the next node. In this fashion, the list can be traversed. Now, as long as there is a pointer to something, the traversal will continue. Once it reaches a null pointer (or dummy node), meaning there are no more nodes (train cars) then it will be at the end of the list, and a new node can subsequently be added if so desired.
