Variations of pointer declarations with const qualifier

The example presents four different syntaxes for applying const to pointers. It is necessary to clarify the meaning of each form: what data can be modified, which pointers can be reassigned, and how to correctly interpret each line.

int value = 1000;

const int* cont_int_ptr        = &value;
int const* int_const_ptr_1     = &value;
int* const int_const_ptr_2     = &value;
const int* const const_int_const = &value;