Difference Between List and ArrayList ?

List is an interface and ArrayList is an implementation of the List interface.
The arraylist class has only a few methods in addition to the methods available in the List interface
http://www.javabeat.net/qna/9-difference-between-list-and-arraylist-/

What are key differences between ArrayList vs Vector in Java ?

Vectors are synchronized, ArrayLists are not.
Vectors are safe-thread as Vectors are synchronized

Both are dynamically resizable.
By default, Vector doubles the size of its array when its size is increased.
But, ArrayList increases by half of its size when its size is increased