So currently I'm learning Javascript from a Python background. I like Javascript but lately there is talk about how you can use it for backend and I'm not sure how that works.<p>Someone explain to me these tools and how they all fit together to build a production site? or even a simple blog perhaps.<p>Javascript, jQuery, Nodejs, Backbonejs, Expressjs, Underscorejs and bower and NPM, Angularjs, Emberjs.<p>I'm having hard time understanding how these all fit together and how they help each other or use to build a website both frontend and backend, thanks.