"narrated" is the past participle of the verb "narrate" --> to give an account of something, for example "description / commentary"
"narrative" is an noun meaning "an account of something" for example "chronicle / history / record"
Even though these seem to have specific technical meanings, the old-fashioned rule applies. Please give us the contexts in which you have seen them, including the specific sentences in which they are used.
Narrative time is used as Loob describes, but it also sometimes refers to other aspects of the relationship between the time the story is ostensibly being narrated in relation to the time in which the events took place.
Edit: Though this repeats timpeac's request, which was posted as I was writing this, I'll let it stand.
Well, I have no concrete example. It's just a question on the novel Heart of Darkness( by Conrad) that one of my teacher asked me and that I cannot explain. I really have a problem with this terms: I've found the definitions on internet but I still do not understand the difference.