What category of data includes the Boolean logical type?

A pointer is a variable that stores the memory address of another object. It can be changed, redirected to different objects, and pointer arithmetic can be performed (e.g., moving to the next element of an array).

A reference is an alias for an existing variable. It must be initialized when created and cannot be reassigned to another object. References are safer because they do not allow null values or arithmetic.

Example in C++:

int a = 10;
int* ptr = &a; // pointer to a
int& ref = a;  // reference to a

*ptr = 20; // changes a via pointer
ref = 30;  // changes a via reference

Main difference: a pointer can be null and can change the address it points to; a reference always refers to one object and cannot be changed after initialization.