AngularJS Basic terms

Today we will try to understand the basic terms used in Angular. 

Injector -
Injector is responsible for assembling the application. We might have multiple services, controllers etc, which might be interdependent. injector take cares of initializing the prerequisite of any of the services, controllers.

Module -
Module is something which configures the injector. It tells the injector what all we have in our scope. anything defined in given module will be visible to injector. Once we create service or controller or anyother component in a single module, all will be linked together via injector. You can visualize module to be a container where all your components like service/controller etc will be defined and injector will manage them. components inside one module will directly wont be visible outside the module.

Scope - The scope in Angular is very much same as JavaScript scope. Scope defines the boundry of your code. Example  - in view we define the controller. The scope of that controller is very much limited to that view only.

<Div ng-controller='myCtrl' > </Div>
myCtrl is the controller which is nothing but a javascript function. Anything you define in this function will be available to this Div element. Hence we can say the scope for this controller is the mentined Div element.
this concept can be visualized with following diagram(taken from Angular official docs) -

rootScope -
rootScope is parent of all scopes. It is the scope of your module. you can access any scope from rootscope.

Directive -
Directives are custome html, which lets you teach html new tricks. for example say there is no tag in HTML named as "list". You can create a tag named as list using directive and write code to give list like behavior to this tag.

Other key words(Won't go into the details) -
Model - Application Data
View - What user sees
Controller - application behavior
$- angular namespace