A liar knows the truth and withholds it. An unreliable narrator often has no idea anything is wrong — a child, a self-deceiver, someone whose moral frame the book quietly declines to share. The best examples are sincere.
Side by side
Aspect
Unreliable narrator
Lying narrator
Knows they mislead
Often not
Yes
Measured against
Implied author
The facts
Can be sincere
Yes
No
Reader's job
Reconstruct
Catch out
What each one means
Unreliable Narrator
A narrator whose account you cannot take at face value — because they are lying or concealing, because they are naive or self-deceived, or because, in Wayne Booth's formulation, they do not speak or act in accordance with the norms of the work.