[Pharo-users] What is the difference between a form and a morph?

I usually like to go through the source code to answer my own question, but I can't tell by reading it. [Morph], from what I understand, deals with manipulating graphics on smalltalk. But when I use ZnEasy to get a jpeg file, I notice that it returns a [Form] and not a [Morph] to display a jpeg. Spec2 also wants [Form] for displaying images rather than [Morph]. So what is the difference between a [Form] and a [Morph] since they both seem to deal with graphics?