Can someone explain me this code?

Question

I wasn't able to understand this code so I have copied and pasted this as it is. I'm new to coding so please keep the explanation simple. It's from C++
#include <iostream>
using namespace std;

int main()
{
int num = 1;
int number;
int total = 0;

while (num <= 5) {
cin >> number;
total += number;
num++;
}
cout << total << endl;

return 0;
}