The Unreliable narrator is a narrator of a story whose credibility has been compromised. This can happen when the character that narrates the story has a problem with another character or has a mental problem or problems with maturity. An unreliable narrator holds a distorted view of the events which leads to an inaccurate telling of the story.
The central idea of a passage is summing up everything that has been said. You take the valuable information from the passage and put it into a few sentences.
