There's no universal programming language for web development, you should first consider your situation and then choose the appropriate programming language for development.
I'll list a few programming languages I use most of time in web programming:
*. HTML: Markup language for presentation layer
2. CSS: used for layout and styles
*. JavaScript: a client programming language often used for user interaction, data processing on browser. anyway, since Node.js and other software used V8 as its interpretation engine, so your JavaScript code will also run on them, but the API it offers might be different from the one running in the browser. There are plenty of mature and stable frameworks/libraries for both frontend and backend apps.
Frontend: jQuery, Backbone.js, ember.js, Angular.js etc.
Backend: Express.js on Node.js etc.
4. SQL: You may need to save your data in a db or data store
5. Other programming languages for backend development: PHP, Java, Python, Ruby and so on.

A very simple architecture for web development:

HTML/CSS/JS for frontend programming, Node.js/MongoDB for backend (you may also want to use rational database such as mysql, just take the place of MongoDB)
Hope i offered some help for more info you can visit http://codeandco.ae/
Connie