title: CORS issue doesn't occur when using POSTMAN
body: <p>I have been using POSTMAN for sometime now for sending <code>HTTP requests like GET, POST, PUT</code> for RESTful Webservices. Recently came across a situation, when sending a request to my REST API through browser, I got a message that </p>
  
  <blockquote>
    <p>No Access Control Allow Origin Header is present on the Requested resource.</p>
  </blockquote>
  
  <p>The solution was ofcourse to add such an header to the API. 
  However strangely, When I sent the the same request through POSTMAN I was able to get back the response.</p>
  
  <p>So I want to know how is sending a request through POSTMAN different from sending a request through browser.</p>
  
  <p>I went through this question: <a href="https://stackoverflow.com/questions/36250615/cors-with-postman">CORS with POSTMAN</a>, but it really doesn't provide an answer in detail.</p>