A brief release history of Angular

Angular has had several major releases during its lifetime. Each release introduces new features and functionality, and each new release can include changes to how the Angular framework works. Developers may have to update their code to reflect the new way Angular will work in a new release.

Having to change your code to work with new releases of software you use is a common thing developers have to do. Usually, though, makers of frameworks and tools for other developers usually do try to ensure backwards compatibility or avoid making problematic changes.

From the second major version of Angular, updating to a new version of the Angular framework is relatively straightforward and simple to do.

But you cannot just update to AngularJS

Between AngularJS, the first version of Angular, and the second version (i.e. Angular), the framework underwent so many changes that the second version was essentially a different framework from the first version. This means that a programmer who used AngularJS to build a web app would have to rewrite their entire application from the ground up using the new version of Angular.

AngularJS and Angular have different names to reflect that they are so different from one another that you cannot use AngularJS and then move to Angular.

Developers who use AngularJS have to rewrite their web apps

AngularJS has reached the end of its life and support. This means that developers who used AngularJS will need to rewrite their web appications. They cannot just update to a newer version of Angular, unfortunately.