A plot summary should briefly summarize the main elements of the story, including the main characters, setting and conflict. It should also include an overview of the plot, focusing on main events and leaving out non-essential details.
The goal of a plot summary is to give readers a basic understanding of the story, which includes introducing them to characters and essential plot points. You try to avoid specific details, such as a characters' appearance, unless it plays a pivotal role in advancing the story.
A good plot summary answers basic questions of who, what, where and when and does not necessarily deal with why things happen. The format of a summary will vary slightly depending on who it is being written for. A book report should include a full synopsis of the plot, while a review or dust jacket summary will introduce readers to the book while omitting some details, such as the ending in order to entice readers into reading the book.
Aim to keep your summary under 300 words. If your summary is longer than this, it likely includes unnecessary information that can be eliminated. Remember to focus on introducing characters, briefly setting the scene and relating major plot points.