How is XML being used for a game engine, here?

Question

In this question, the first answer explains a way of defining components of a gaming engine in XML, like this:

<?xml version="1.0" encoding="UTF-8"?>
<mobs>
  <mob>
    <personality>Aggressive</personality>
    <intelligence>20</intelligence>
  </mob>
</mobs>

Then, states in Java that your mob class would look like this:

public class Mob {
  private IPersonality personality;
  private Integer intelligence

  //**  Getters & Setters **//
}

What exactly is the XML doing, here? I'm not really familiar with XML, at all.

Answer 1

The XML describes one instance of a mob, i.e. the traits of one specific mob (it's personal personality and intelligence).

The Java class describes the general structure of all mobs (their traits: personality and intelligence).

Typically, a game engine would serialize the XML data at runtime to create actual Java Mob objects (= instances of the Mob class).

Answer 2

Maybe I didn't explain fully,

You implement the loading of the XML to the Class instance ensuring meaning in theory it could just as easily be any data format, json, flat file, Database its how you use the data that decides what it means. The example i provided was instantiating a new instance of IPersonality based on the String within the tags

 public IPersonality getPersonality(String personalityName) {
      if(personalityName.equals("Aggressive")) {
        return new AggressivePersonality();
      }
      else if(personalityName.equals("Passive")) {
        return new PassivePersonality();
      }
      else {
         //Maybe allow for no personality (We all know monster like that ;) )
         return null; 
      }
    }

Here I saying if I find the name aggressive this mob the aggressive personality component.