clone-deep is a utility for creating deep copies of JavaScript values, including objects, arrays, and primitive types. It recursively duplicates all nested structures, ensuring that the cloned object is completely independent of the original. This avoids unintended modifications to the original data when working with the copied version. clone-deep handles circular references and ensures data integrity during the cloning process, making it suitable for scenarios where preserving data immutability is crucial. It is a popular choice for preventing side effects when working with complex data structures.