Exposition
You all know Mr. Exposition. He's the character who says, "Well,
Jim, as you know, the Chopec are a people who live in Peru but occasionally
take ocean voyages to Cascade in order to seek out the heads of corporations
that are destroying their lands." His is a thankless job, that
of explaining to the readers who a character is and exactly what is
going on, or of giving background information. Sometimes, she is Ms.
Exposition, or Dr. Exposition, but the job is always the same. In bad
writing, Mr. Exposition has no other purpose as a character than to
dispense information. He is not really a person at all, but a walking
encyclopedia. In the worst writing, Mr. Exposition is not a character,
but the writer himself, giving the readers lots of information in blocks
of not very interesting prose. This is also called info-dump.
Info-dump is to be avoided whenever possible. Yes, some information
does need to be given straight out, but a good writer tries to find
an interesting way to do that. MOST information should be woven into
the story in such a way that the readers are not consciously aware that
they have been sucking it into their brains. It is more fun for the
readers to believe they have discovered such tidbits on their own than
to have info-dump forced upon them in large, unpalatable chunks. This
leads us to the most important rule in fiction writing: