Theme is what the author is trying to tell the readers, Example: In little red riding hood she went to go see her granny who lived in the woods and her mom told her not to talk to strangers, but on the way there she stopped and talked to a wolf who stopped her in her attacks and she told him where she was going.
The theme of this story is never to talk to strangers and to never give out your personal information or you could end up like little red riding hood did