title: No proper definitions for the types of artificial agents
body: <p>I have been searching for the definitions of the following:</p>
  
  <ol>
  <li>Reflex agent</li>
  <li>Model-based Agent</li>
  <li>Goal-based Agent</li>
  <li>Utility-based Agents</li>
  </ol>
  
  <p>But I couldn't find anything. Most of the websites explain each with 2 sentences and one diagram which is kind of abstract. May be I am not good enough to understand them. </p>
  
  <p>I really appreciate, if someone explain them in proper English.</p>