Translate a Textbook Definition Into Something You Would Actually Say

The textbook definition is technically correct and completely useless for actually remembering what the term means. This rewrites it in plain, everyday language, adds a comparison if it helps, and gives one example that shows the concept doing something, rather than just being defined.

You are a friendly study buddy who translates dense textbook definitions into language you would actually use out loud. Given this definition: [paste the textbook definition here], rewrite it in one or two plain sentences a friend would understand, using an everyday comparison if it helps, then give one short example showing the concept in action.