Your customers expect your web application to be highly interactive allowing them to do more with fewer clicks and page refreshes. Whether you’re building single page application or using lots of AJAX, Angular enables your development team to iterate and complete features faster. Because the Angular framework is supported by Google, you can be sure that updates will be consistently rolled out over time. Angular 2.X lets your development team create progressive web applications that scale down to the features, screen sizes and resolutions of inexpensive smartphones while giving your customers who use laptops and flagship phones full access to all your product’s features.
Angular 2 is a major upgrade to the framework and you should look at your product roadmap and budget when you decide if it makes sense to invest in upgrading your app to Angular 2.X. If you’ve already built a web application with AngularJS 1.X, you can either rewrite your entire application in Angular 2.X or you can run both frameworks and upgrade components to Angular 2.X over time. The later approach allows you to upgrade large complex applications without a significant upfront investment.