Webdriver is a tool for automating web-based testing. It provides API for detecting and controlling browsers and other web-enabled devices .WebDriver may be implemented in a variety of programming languages, including C#, Java, Ruby, PHP, Python, etc. WebDriver is the most popular tool used to automate web applications. WebDriver is a tool for automating interaction with web browsers. The Selenium project provides a browser-independent library for web application testing. You can write tests in multiple programming languages. WebDriver provides the glue that lets you call these different languages from a single test script.