HTML enhanced for web apps!
More technically, it is a flavor of an MVC framework useful when designing front-end web applications (and even hybrid mobile applications if you use in conjunction with the ionic framework).
So when we develop any web applications what we need?
answer is mainly 3 things.
First is front end second is server and third is database.
Now the second part is server. By server means the system doing your a lot of task and located in simewhere else in any corner of the world. What are the tasks which you work on the server side? Answer is fetching data from database, processing them to required output and sending the processed data to the client side. Which is the end user. Node.js is the server side scripting language. Whatever you do on the server side you can do this it in node.js. like php is another server side language. You can write client side program with these languages. When you send data to client side after processing them. It is the the task of client side language to handle them and showing them to user. And that is what angular does.