The WebDriver is one of the best features about the BotMan library. Still I see a lot of people struggling with the concept and how to use it. Let's clear things up and let me show you how I already used this driver in production.
He starts off by talking about chatbots in general and how they're "more than just messengers" and can provide more real-time information to visitors to your site. In order to enhance the basic bot functionality, it needs to work with another source - in this case an API accessed via the WebDriver. He then gets into some example code showing how to use the driver to access an API and some explanation of the pieces involved.