Difference between iterator and index access

Index based access allow access of the element directly on the basis of index. The cursor of the datastructure can directly goto the ‘n’ location and get the element. It doesnot traverse through n-1 elements. So this is like random access, as it is in case of arrays.

In Iterator based access, the cursor has to traverse through each element to get the desired element.So to reach the ‘n’th element it need to traverse through n-1 elements. So this is the case of linked list, where we have to go through each element to insert something in list.

Insertion,updation or deletion will be faster for iterator based access if the operations are performed on elements present in between the datastructure.

Insertion,updation or deletion will be faster for index based access if the operations are performed on elements present at last of the datastructure.

Traversal or search in index based datastructure is faster.

ArrayList is index access and LinkedList is iterator access.