3. Understanding and Preventing the "TS2532: Object is possibly 'undefined'" Error
   Error: TS2532: Object is possibly 'undefined'Meaning: This error occurs when TypeScript encounters a variable or property that might be undefined during runtime
4. Example Codes:
   NullInjectorError: This error indicates that Angular's dependency injection system couldn't find a provider for the AngularFirestore service when you tried to inject it into a component or another service
5. Unlocking Reactive Data Flows: Converting Promises to Observables in Angular with Firebase and RxJS
   Promises: Represent a single asynchronous operation that eventually resolves (with a value) or rejects (with an error). They're a fundamental concept for handling asynchronous tasks