Angular JS ,Angular 2 , Angular 4 differences

https://www.angularminds.com/blog/article/comparison-difference-between-angular1-vs-angular2-vs-angular4.html

Angular JS - 2010
Angular 2 - 2016
Angular 4 - 2017

1st version of angular is called Angular JS.
some people called angular 1, but officially it is angular js
--> Angular js concept is based on controllers. To glue a controller and view in Angular JS we used $Scope.
Angular 2 , $Scope and controllers are gone. It is entirely component based, which means it creates a set of independent or loosely coupled components and put them together to create a angular js applications.
So, Component is the building block of Angular 2 applications. Advanatage of this is that, code reuse.
ex: if you have a rating component you may use it on an employee page or product page to rate it.
Angular JS was not built for mobile devices, whereas Angular2 on the other hand it is designed to ground up with the mobile support in mind.
Angular 2 , we have more language choices (Javascript, Typescript, Purescript etc..)


Angular 2 to Angular 4:
Angular 4 is simply next version of Angular 2.
Angular 4 is backward compatable for angular 2 applications.
New Type script version we can use in Angular 4
Animation features are pulled out from the @angular/core and moved into their own package.
New IF /ELSE sytle syntax with *ngIf structural directive.