Greedy,Reluctant,Possessive Quantifers?

[Dillinger4]

Anyone know what the similarities or differences are between these quantifers? Under the docs the descriptions are all the same.

Greedy quantifiers
X? X, once or not at all
X* X, zero or more times
X+ X, one or more times
X{n} X, exactly n times
X{n,} X, at least n times
X{n,m} X, at least n but not more than m times

Reluctant quantifiers
X?? X, once or not at all
X*? X, zero or more times
X+? X, one or more times
X{n}? X, exactly n times
X{n,}? X, at least n times
X{n,m}? X, at least n but not more than m times

Possessive quantifiers
X?+ X, once or not at all
X*+ X, zero or more times
X++ X, one or more times
X{n}+ X, exactly n times
X{n,}+ X, at least n times
X{n,m}+ X, at least n but not more than m times

Also how are these quantifers used? I made a simple test program using the greedy,reluctant,possessive quantifiers(X, once or not at all) quantifers
but i don't understand the output.

 import java.util.*;
 
 public class X{
  public static void main(String[] args){
 
   String data = new String("mxpxr");
   Scanner s = new Scanner(data);
  // s.useDelimiter("x"); //  returns mpr
  // s.useDelimiter("x?"); // returns mpr{greedy quantifer}
  // s.useDelimiter("x??");  // returns mxpxr{reluctant quantifer}
  // s.useDelimiter("x?+"); // returns mpr{possessive quantifer}
   while(s.hasNext()){
     System.out.println(s.next()); 
   }
  }
 }