If you have used Selenium before, you might be amazed at how easy it is to manipulate a fully functioning browser in just a few lines of code. On the other hand, if you have used Selenium before to run a long test, i.e., to scrape a long list of URLs that require javascript. You will be also disappointed that how slow it could be, comparing with non-javascript calls. Here, Selenium Grid is will scale Selenium Test easily and run Selenium Test in parallel. 

In this post, I basically followed the Selenium Grid 2 tutorial, and got the Selenium grid working. One thing that worth mentioning is you had better download a standalone Selenium server that will be compatible with you browser version. Low hanging fruit might just be going after the latest Selenium build. 

As you can see, instead of do `new Firefoxdriver`, you can just describe your browser capability, and the hub will assign the right resource to you. 

Also, you don’t have to write Java code and there is a great tool called Selenium IDE that will track your activity inside a browser and generate test script based on that recording, and it can the exported to all different types of languages and format. Junit, Python Test ..etc.

Here is a video from youtube by Ghafran helped me a lot!