If it's based on real events that one man has witnessed or participated in, that makes it a true story. For instance, if he's writing about his wartime experiences.
It's hard to say for certain. You'd need to look into the background and author's intentions. Some stories are inspired by real life but are not strictly true in every detail.
The Man in the Moon is not based on actual events. It's a fictional tale that has been passed down through generations for entertainment and imagination.
Definitely true. The character of the Elephant Man was inspired by the actual experiences of Joseph Merrick, who faced significant physical challenges and hardships in his life.