What is derivative example?

Could you please elaborate on the concept of a derivative, and provide me with a specific example to help me understand it better? I'm particularly interested in how derivatives are used in the realm of finance and cryptocurrency, as I'm trying to broaden my understanding of these complex topics. Could you explain how derivatives work, and perhaps give me a real-world scenario where they might be employed? It would be greatly appreciated if you could keep your explanation concise and easy to follow. Thank you for your assistance.