I'm trying to reproduce a picture and I'm having a problem (since this is my very first experience with tikzpictures). The picture is the following:
My problem is of how to create the part that is inside the frame in the middle and more precisely how am I supposed to "frame" it like that (with the underlying part - description) and connect it later with the other nodes I have.
Sorry if the question is very naive. Thanks in advance for any help.