title: Read/Write operations in MEAN.js
body: <p>I have just started with <code>mean.js</code>  and am confused about its work flow. I created a new module using yo man generator. I need to be clarified about</p>
  
  <ul>
  <li>How a record is been added to the database ie where are the queries.</li>
  <li>How can a record be updated</li>
  </ul>