A summary is a short version of something longer that captures the main points. When you write a summary of a book chapter, you explain what happened and what mattered most, leaving out smaller details. A good summary gives someone who hasn't read the original a clear sense of what it contained.

The key to summarizing is deciding what's essential. If you read a long article about dolphins and then tell your friend, “Dolphins are really smart and use special sounds to communicate,” you've created a summary. You skipped the details about specific dolphin species and exact frequencies of their clicks, keeping only the central ideas.

Teachers often ask for summaries to check whether you understood the important parts of what you read. In meetings, someone might summarize the discussion before everyone leaves, reminding the group what they decided. Scientists summarize their research findings. Journalists summarize the day's news.

The verb form is summarize. When you summarize effectively, you show you can tell the difference between what's crucial and what's just interesting background. Being able to create a clear, accurate summary is a valuable skill: it means you truly understood something well enough to explain its main idea to someone else.