Pointers are used to store the address of variable.
Type *pointer; pointer = variable name;
When a variable is declared as reference, it becomes an alternative name for an existing variable.
Type &newname = existing name;
Type &pointer; pointer = variable name;
The main differences between pointers and references are -
References are used to refer an existing variable in another name whereas pointers are used to store address of variable.
References cannot have a null value assigned but pointer can.
A reference variable can be referenced by pass by value whereas a pointer can be referenced but pass by reference.
A reference must be initialized on declaration while it is not necessary in case of pointer.
A reference shares the same memory address with the original variable but also takes up some space on the stack whereas a pointer has its own memory address and size on the stack.