Angular and node are Both the open-source tools as node.js is mainly used to build server-side applications, whereas Angular is suited for building single-page client-side web applications both can be combined to create isomorphic web applications, i.e. applications that are built with the same language on the back and front-ends, but they are quite different in their architecture and working. If you go a little further and use MongoDB as your data store, you can build your entire infrastructure using JavaScript favored tools.
This is a huge gain for developers since they can focus on learning only one language and be MEAN-stack developers.
Reference:
https://www.angularminds.com/blog/article/comparison-between-angularJS-vs-node-js.html