WebDriver is a remote control interface for user agents that allows introspection and control. It provides a platform- and language-agnostic wire protocol that allows out-of-process programmes to remotely control web browser behaviour.
Selenium jar files contain WebDriver, which is a user interface. webDriver refers to a variable called driver. The term new is used to create a class instance. Furthermore, Selenium already has a FireFoxDriver() class. As a result, you can import it and use it for your test immediately.