The `ngAfterContentInit` and `ngAfterViewInit` hooks are both lifecycle hooks in Angular, but they are used in different contexts and serve different purposes. `ngAfterContentInit` is a lifecycle hook that is called after Angular initializes the content projected into a component. It is used when you need to perform initialization or setup logic that depends on the content projected into the component. This hook is typically used in components that have `<ng-content></ng-content>` tags in their templates to project content from the parent component. You can access the projected content using the `@ContentChild` decorator. On the other hand, `ngAfterViewInit` is a lifecycle hook that is called after Angular initializes the component's view and its child views. It is used when you need to perform logic or operations that require access to the component's view or its child views. This hook is often used for DOM manipulation, accessing ViewChild elements, or interacting with third-party libraries that require the view to be fully rendered. You can access the view elements using the `@ViewChild` decorator. Here's a summary of the key differences between `ngAfterContentInit` and `ngAfterViewInit`: 1. Purpose: - `ngAfterContentInit`: Used for initialization or setup logic dependent on projected content. - `ngAfterViewInit`: Used for logic or operations that require access to the component's view or child views. 2. Timing: - `ngAfterContentInit`: Called after content projection is initialized. - `ngAfterViewInit`: Called after the component's view and child views are initialized. 3. Decorators: - `ngAfterContentInit`: Use `@ContentChild` decorator to access projected content. - `ngAfterViewInit`: Use `@ViewChild` decorator to access view elements. 4. Usage: - `ngAfterContentInit`: Typically used in components that project content from parent components. - `ngAfterViewInit`: Typically used for DOM manipulation, accessing view elements, or interacting with third-party libraries. Conclusion: In summary, `ngAfterContentInit` is used when you want to perform initialization based on projected content, while `ngAfterViewInit` is used when you need to perform logic or operations that require access to the component's view or child views.