The “Big Three” in C++ refer to three essential member functions in a class:

Destructor (~ClassName()): Cleans up resources (e.g., dynamic memory) when an object is destroyed.

Copy Constructor (ClassName(const ClassName &other)): Creates a new object as a copy of an existing object, ensuring proper duplication.

Copy Assignment Operator (ClassName& operator=(const ClassName &other)): Assigns the values of one object to another, managing resources and avoiding memory leaks.