title: Is this correct - FirefoxDriver driver = new FirefoxDriver();?
body: <p>I have seen almost everybody using the statement <code>WebDriver driver=new FirefoxDriver();</code> here we have created an instance of <code>FirefoxDriver</code> class having type as <code>Webdriver</code>; 
  What if i directly create an instance of FirefoxDriver as <code>FirefoxDriver driver = new FirefoxDriver();</code>
  I have gone through many discussion where it is said that Webdriver is an interface. I know what interface is and how it works. I want to know if  <code>FirefoxDriver driver = new FirefoxDriver();</code> is correct when i know that Firefox is the only browser i am gonna use in my selenium script?</p>