enum – what are they

A enum type is basically a array on constant elements that you can assign to words a integer value.

To give a example, lets say that you have a different type of car

enum cars { VAUX, FORD, LAND };

which in turn mean that VAX = 0 and FORD = 1 and LAND = 2, arrays start from 0 of course.

So you can use the code as

enum cars car = VAUX;
if (car == VAUX) printf("Vauxhall car\n");

which would make more sense than saying

int car = 0;
if (car == 0) printf("Vauxhall car\n");