Linked List
A data structure that represents a sequence of nodes. The head points to the first node.
A linked list does not provide a constant time access to a particular index within the list. If you want to find the kth element in the list,
you need to iterate through k elements.
-Can add and remove elements of the list in constant time.
Singly Linked List
Each node points to the next node in the linked list.
Doubly Linked List
Each node has pointers to the previous and the next nodes.