What is the difference between Lists, ArrayLists, Maps, Hashmaps, Collections etc..?

Question

I\'ve been using HashMaps since I started programming again in Java without really understanding these Collections thing.

Honestly I am not really sure if using HashMaps

Answer 1

In Brief (and only looking at interfaces):

List - a list of values, something like a "resizable array"

Set - a container that does not allow duplicates

Map - a collection of key/value pairs