What is selenium web driver and what is does?

What is selenium web driver and what is does?

Selenium web driver is open source Testing tool which support of many browsers.
it is also supporting many different languages like python, ruby, c#, java, PHP and perl also..
selenium web drive was developed to better support dynamic web pages where elements of a page may change without the page itself being reload.
Web driver goal is to supply a well designed object oriented API that provides improved support for modern advanced web app testing problems

simple program of selenium web driver to open the webpage

public class A {

/**
* @param args
*/
public static void main(String[] args) {
WebDriver driver=new FirefoxDriver();
driver.manage().window().maximize(); //for maximize the window size
driver.manage().timeouts().implicitlyWait(10, TimeUnit.SECONDS); //implicitly wait
driver.get("http://www.americangolf.co.uk/golf-clubs/putters");


}

}