Not the elegant prince of our debauched and vicious art, not the jeweled idol of our society churches--but the Jesus of the awful reality, the man of sorrow and pain, the outcast, despised of the world, who had nowhere to lay his head--.
Service is singleton and simple version of Factory. While Factory is a simple version of Provider, Factory is a more flexable compared to service method, and a short handed for configuring a service when $get method is required. Provider creates new object by the $get factory function. Provider is not injectable during run phase or run time while all others are ( Constant, Variable, Service, and Factory), however, Provider is injectable during the configuration phase or compile time.
The AngularJS library works by first reading the HTML page, which has embedded into it additional custom tag attributes. Angular interprets those attributes as directives to bind input or output parts of the page to a model that is represented by standard JavaScript variables.ngularJS's design goals include: 1  to decouple DOM manipulation from application logic. 2  to decouple the client side of an application from the server side. 3  to provide structure for the journey of building an application: from designing the UI, through writing the business logic, to testing.