I am a angularJS developer, But like to learn the ionic framework, Can any one of you tell me how can the angularJS will help me in learning the Framework. Or is it like, It is entirely different from angularJS features
Bear in mind that Ionic is a UI framework that leverages Angular; your existing experience with Angular will help you learn it simply by virtue of the fact that you won't have to learn Angular and things like databinding, $scope, etc. but you'll still need to familiarize yourself with the UI framework (e.g.: menus, status bars, scroll areas). In practice it's not much different from a UI framework such as Zurb Foundation, and the APIs/CSS are pretty well thought-out.
I would also recommend that you use their (still growing) tutorial site.