Dynamic casting is a feature in programming languages like C++ that allows you to safely convert pointers or references of one type to another within an inheritance hierarchy. It is particularly useful when dealing with polymorphism, enabling you to check at runtime whether an object is of a specific derived type before performing operations on it. When using dynamic casting, if the cast is successful, it returns a pointer or reference to the derived type; if not, it returns a null pointer or throws an exception. This ensures type safety and helps prevent errors that could occur from invalid type conversions.