is delivery status notification a return email or smtp log line?

[Dica]

i think i've gotten the wrong idea about the differences between a read
receipt and delivery status notificaiton. i was assuming that delivery
status notificaiton is a response line from the remote smtp server that
would be added to the originatoring smtp server's log file. but that's not
it, is it? delivery status notification means an email is generated and sent
to the recipient's email box, correct?