We will now take a look at the various drivers that are available in Selenium and their usage.
Drivers in Selenium
Remote WebDriver
Remote WebDriver is the implementation class of the WebDriver interface. Apart from WebDriver, it also implements the interfaces of TakesScreenShot, findBy, JavaScriptExecutor, and so on.
Mobile drivers
All modern web apps have implementations for mobile devices. The two most popular operating systems in mobile devices are Android and iOS. Selenium has implementations for Android and iPhone, that is, AndroidDriver and IODDriver. Both of these are direct implementations of WebDriver.
Headless browsers
Headless browsers are those that do not have a graphical user interface (GUI). Everything runs in the background. When a test is executed with a headless browser, no screen is displayed to the user. Two popular headless browsers are HTMLUnit and Phantom JS. Chrome now supports the HTMLUnit browser.
Why do we need headless browsers?
Suppose that Selenium tests have to be executed on an OS which does not have a GUI like Linux or when multiple browser behaviors have to be simulated on just one machine. The advantage of a headless browser is that the resources utilized by the test are minimal. A scenario where you can use these browsers is for test data creation. In these situations, there is no special need to display the screen to the user.