a = b; Help?

[iPirate]

Ok im a bit stuck with Operators. I have this code, but dont know what some parts mean.

#include <iostream>
using namespace std;

int main ()
{
     int a, b=3, c=1, d=5;
  
     a = b;                     << What do these parts mean?
     c = d;                      << ???
  
     c+=1;
     d+=2;            
     cout << d;
  
    cin.get();
  
    return 0;
}

Thank you!