[c++] Why does rand() yield the same sequence of numbers on every run?

Every time I run a program with rand() it gives me the same results.

Example:

#include <iostream>
#include <cstdlib>

using namespace std;

int random (int low, int high) {
    if (low > high)
        return high;
    return low + (rand() % (high - low + 1));
}

int main (int argc, char* argv []) {
    for (int i = 0; i < 5; i++)
        cout << random (2, 5) << endl;
}

Output:

3
5
4
2
3

Each time I run the program it outputs the same numbers every time. Is there a way around this?