[noob][c++] what is enum and how do I use it?

can you show me a small piece of code?  (as small as possible, like, 3 values.)

#include <iostream>
using namespace std;
 
enum e_usflcnst{
      CATLIFE_FACTOR = 7
};
 
int main()
{
      int age;
      cout << "Enter your age: ";
      cin >> age;
      age /= CATLIFE_FACTOR;
      cout << "If you were cat, you would be " << age << endl;
}







this makes sense,

but what I don't undersrtand it,  why not just use a variable for the factor?

also, what role does e_usflcnst  play here?

i don't understand,

I get it that raidbowcolors is a enum type (just like int and double, it's a type of variable ) with elements (colors)


but then how are you using it?

is it like a way to use strings without having to use string variables?



so a type rainbow can have only those variants of colors , can I alter rainbow afterwards?

also, I have to assign only those elements I already define in the enum type right?

for instance I can't do


rainbow trafficlights = silver



also, I don't need to quote colors?

thank you all SO much !