Angular Dependency Injection

Dependency Injection (DI) is a core design pattern in Angular. It allows classes to receive their dependencies from an external source rather than creating them internally.

Key concepts:

• Injectors: Responsible for creating and providing instances of dependencies.
• Providers: Define how a dependency should be created (e.g., providedIn: 'root').
• Tokens: Unique identifiers for dependencies.
• Hierarchical DI: Different levels of injectors (root, platform, component-level) allow for flexible scoping of services.