Throughout this book, we used Selenium ChromeDriver to test with Protractor. What this meant was that in order to run a Protractor test, we simply had to have the website running and then kick off Protractor. In Chapter 3, End-to-end Testing with Protractor, ChromeDriver was installed and used to run the tests. From the perspective of the book and TDD, this was acceptable. Our tests were small and contained and did not have a lot of moving parts.
The problem with only using ChromeDriver is that we can't test on other browsers. As your application grows and you want to support more browsers, you need to think about running a standalone Selenium Server. This section of the book provides a walk-through of how to get a standalone Selenium Server running and integrated with Protractor.