random number generator

[Brian_Jones]

After searching the net for an hour to find a good random number generator, this is the best I found. From what I understand it works off of time as seconds and minutes change, but I would like to dive in further to understand the purpose of these 5 items...

srand
rand
time
NULL
<ctime>

#include <iostream>
#include <ctime>
using namespace std;

int main()

{
srand(time(NULL));
cout << rand();

}