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What Is Injector tree? In the Dependency Injection guide, you learned how to configure a dependency injector and how to retrieve dependencies where you need them. An application may have multiple injectors. An Angular application is a tree of components. Each component instance has its own injector. The tree of components parallels the tree of injectors. Three level component tree –  What Is Injector bubbling? Explore in detail by using below questions - 1.        What Is an entryComponents? 2.        What Are @Injectable providers? 3.        What Is Dependency Injection (DI)? I hope enjoy this post. Thank you very much reading this post.

What Are @Injectable providers? The @Injectable decorator identifies services and other classes that are intended to be injected. It can also be used to configure a provider for those services. To inject the service into a component, Angular provides an Injector decorator: @Injectable(). A provider defines the set of injectable objects that are available in the injector of this module. The @Injectable decorator marks a class as available to an injector for instantiation. An injector reports an error when trying to instantiate a class that is not marked as @ Injectable . Injectors are also responsible for instantiating components. At the run-time the injectors can read class metadata in the JavaScript code and use the constructor parameter type information to determine what things to inject. Injectable decorator and metadata - @ Injectable ({   providedIn? : Type < any > | 'root' | null   factory : () => any }) To inject the service ...