title: what is browser's native support according to selenium webdriver
body: <p>While learning about selenium, I came to know that:</p>
  
  <blockquote>
    <p>Selenium 
    Webdriver
    makes direct calls to the 
    browser using each browser’s native support for 
    automation</p>
  </blockquote>
  
  <p>I want to know, What is this native support? Is it "some HTML code", or "javascript code"? </p>
  
  <p>Is there any good web link, where I can know that in what language or script, browsers are written in?</p>