WTF are Linked Lists?

Linked lists are different from arrays in their structure. The number of nodes in a linked list is not fixed and can grow and shrink on demand. Every element of the list is represented by an object with two fields. This object is called a node and first field of the node we often call head while the second field is pointing to the next node. To add a node as the last element, you changed your mind and you want to go on the end of the row, you must pass all people one by one till you arrive till the end. To insert node on the desired position we can make things easier and write the helper method that will return the index of the linked list.