Angular is a platform that makes it easy to build applications with the web. Angular combines declarative templates, dependency injection, end to end tooling, and integrated best practices to solve development challenges. It is a great framework but it dosent have any out of the box rich UI components like datatables, grids etc. PrimeNG is a collection of rich UI components for Angular. All widgets are open source and free to use under MIT License. PrimeNG provides good documentation that can be used for making use of the widgets provided by them.