Problem of Singly List :

They have only one single link with other node . They have no back option . Their complexity to back by recursion is O(N) . There is no option to come from 99th node to 98 node by one option .

Doubly Linked List :
It will have the address of previous node and next node .

By using it we will be able to traverse from right to left by doubly linked list easily using a loop .