difference between pointer and reference in c?

Question

what is the difference between pointer , reference and dereference in c?

Answer 1

A pointer's value is a memory address.

int a;
int* b = &a;
// b holds the memory address of a, not the value of a.

A reference is a pointer with a value (memory address) that refers to a desired item.

int a;
int* b = &a;
// b is a reference to a.

A dereference is a technique of grabbing the memory contents that a pointer references.

int a;
int* b = &a;
int c = *b;
// c dereferences b, meaning that c will be set with the value stored in the address that b contains.

Note that a C++ reference is a different thing than a C reference. A C++ reference is an abstract idea where C++ decides to allow you to use non-pointer syntax for most calls, but will automatically "do the right thing" in passing a pointer when needed.