Using a constructor vs direct initialization

Question

I am trying to use a constructor to declare the strings a1,b1 and also declaring two other strings a2,b2. Upon checking if they are equal, I am getting different responses.

public class Practice {
    public static void main(String args[]){ 
        String a1= new String("Check");
        String b1= new String("Check");
        String a2="Check1";
        String b2="Check1";
        System.out.println(a1==b1);
        System.out.println(a2==b2);
    }
}

Output:
false
true