What is the difference between shallow copy and deep copy?

The distinction between shallow copy and deep copy lies in how they handle complex objects, especially those containing references to other objects.

When a shallow copy is made, it creates a new object but does not create copies of objects that are referenced within it. Instead, it only copies the references to these inner objects. This means that if the inner objects are modified, those changes will reflect in both the original and the copied objects since they are essentially sharing the same references.

In contrast, a deep copy goes further by creating a new object as well as new copies of all objects that are referenced within it, recursively. This results in a completely independent replica, such that changes made to the inner objects of the deep copy will not affect the original object, and vice versa.

This understanding clarifies the nature of object copying in programming, particularly in languages like C where resource management and memory consideration are vital. In this context, recognizing the operational differences between shallow and deep copying is crucial for effective memory and data structure management.