I just learned about how the Java Collections Framework implements data structures in linked lists. From what I understand, Iterators are a way of traversing th
Iterator simply adds a common way of going over a collection of items. One of the nice features is the i.remove() in which you can remove elements from the list that you are iterating over. If you just tried to remove items from a list normally it would have weird effects or throw and exception.
The interface is like a contract for all things that implement it. You are basically saying.. anything that implements an iterator is guaranteed to have these methods that behave the same way. You can also use it to pass around iterator types if that is all you care about dealing with in your code. (you might not care what type of list it is.. you just want to pass an Iterator) You could put all these methods independently in the collections but you are not guaranteeing that they behave the same or that they even have the same name and signatures.