Understand the ListView's view recycle.

Hi!
My name is Mauro and i'm not a new programmer, but i have some difficultes to understand the listview's item work.
I'm using a view holder, and i know that list view reuse the view for re-render it. Now, if i want to access to a direct item's view instance, i think that i can't because it is the same instance.

But, when i use it, it works well and i don't know why. So, my questions are:

"The listview, clone the convertView? I have always the some view instance, only rendered different time in different positions, or it will create difference view instances?"

"If i want to change an image of a ImageView in a item, without using the adapter but accessing directly from a view, how i do it?"
Beacuse i think (i haven't tryed it yet) that if i change an imageView source of a item, it will change it to all other listview item, beacouse it is the same instance/reference!

I'm sorry for my bad english.
Thank you.