An ArrayList uses an array to store its elements. This means it's fast for random access (e.g. get me element #9832), because the array index gets you right to that element. It's slow for adding and deleting at the beginning and middle of …

Object serialization takes an object's state and converts it to a stream of data for persistance. To make an object serializable, the class must implement java.io.Serializable. It is a marker interface; no extra methods need to be implemen…