| Array | Arraylist class |
| It is a fixed length structure and once its created its size cannot be changed. | It is a variable length collection class and can resize itself depending on its capacity and load factor. |
| It cannot use generics as the array instance knows its type and can throw an ArrayStoreException if the array is not convertible. | It allows to use generics to ensure the type-safety. |
| It provides length variable to denote the length of an array. | It provides the size() method to calculate the size of the ArrayList. |
| It contains both the primitives and the objects. | It cannot store the primitives but it can store the objects. |
| Assignment operator is used to store elements in an array. | Add() method is used to store elements in the ArrayList. |
| It is mandatory to provide the size of the array while creating it. | An instance can be created without specifying the size. |
