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 close(), it will only close the window that Selenium WebDriver is currently on. On some implementations of the server-side, or browser code, when we use close() method and it is the last window open, then the server-side code will act as though quit() was called.