Angular is considered one of the best open-source JavaScript frameworks. AngularJS was released in 2010 as a JavaScript framework for building client applications.  As the core had to be further developed and the framework became too complex, the Angular team decided to rewrite the framework with TypeScript and thus in 2016 Angular 2 was released. After that Google’s Angular team released Angular 4 and 5. If you are still learning Angular frameworks, you should have to know  about comparison of Angular 1 (AngularJS), Angular 2, Angular 4 and Angular 5. See the comparison between AngularJS and its different releases till the date.