Dependency Injection

Dependency injection is a process in which a code component defines dependencies on other components. When the code is initialized, the dependent component is made available for access within the component. AngularJS applications make heavy use of dependency injection.

A common use for dependency injection is consuming services. For example, if you are defining a module that requires access to the webserver via HTTP requests, you can inject the HTTP service into the module, and the functionality is available in the module code. In addition, one AngularJS module consumes the functionality of another via dependency.