Diff. between List<Object> and ArrayList<Object>? usage samples?

[Gianni Galore]

I want to define a list of objects. As far as I know one can implement it as

List<Object mylist = new .....

or

ArrayList<Object> mylist = new ....

What is the difference?

Where can I find usage samples for adding and retrieving Objects to/from a pure List?

Gianni