You will notice that in the
tearDown() we call
quit(). We call
quit() because this call cleans up all of the resources that WebDriver starts up and uses. If you were to call
it will only close the window that Selenium WebDriver is currently on. On some implementations of the server-side, or browser code, when we
close() and it is the last window open then the server-side code will act as though
quit() was called.