What is singly linked list and doubly linked list?
Singly Linked list
Each item in the list is called a node and contains two
fields
 Information field - The information field holds the actual
elements in the list
 Next address field- The next address field contains the
address of the next node in the list.
The entire linked list is accessed from an external pointer
called the List.
Doubly linked list is a collection of node. Each node contains
three fields an info field that contains the
information stored in the node. The left and right field that
contains the address of the node on its left
and right. The doubly linked list could be linear, circular and
may have a header node.