Dynamic Memory Management.If the allocated memory is not freed when it s no longer necessary it will result in a memory leak. It is not specified what will happen to the leaked memory, but contemporary operating systems collect it when the program terminates. Memory leaks can be very dangerous because the system may run out of memory. To eliminate them, C++ provides a destructor member for every class where the programmer should deallocate all the memory it allocates inside the class. In other languages like Java or C# a garbage collector is used that figures out which memory blocks are no longer needed and deletes them, taking the burden of deallocation from the programmer s shoulders, but adding some overhead in runtime. In C++, you can use smart pointers that hold on to a piece of memory and deallocate that memory in their destructors.