Difference between ArrayList and LinkedList? When to use which? code example

Example 1: what is the difference ArrayList vs LinkedList

ArrayList is array based, internally uses array
LinkedList consists of nodes/values that are related to each other
ArrayList and LinkedList both keep ordering
ArrayList and LinkedList both allow duplicates

Example 2: arraylist vs linkedlist

- ArrayList not syncronized, array based class 
- LinkedList not synchronized, doubly linked
ArrayList and LinkedList both keep ordering
ArrayList and LinkedList both allow duplicates