What is the difference between a pointer and a reference in c++?

Answer:

A reference must always refer to some object and, therefore, must always be initialized. Pointers do not have such restrictions. A pointer can be reassigned to point to different objects while a reference always refers to an object with which it was initialized.

You can read this post “reference vs pointer“. In which I  have explained the difference between pointer and reference with the help of programming examples.