C has three categories of built-in data types: pointer types, integral types, and floating-point types.
Pointer types are the most restrictive in terms of the operations that can be performed on them. They are limited to
" - " subtraction of two pointers, valid only when both pointers point to elements in the same array. The result is the same as subtracting the integer subscripts corresponding to the two pointers.
" + " addition of a pointer and an integral type. The result is a