Angular is a powerful front-end web application framework maintained by Google, designed to simplify the development of dynamic and interactive web applications. One of its core features is data binding, which allows automatic synchronization between the model and the view. This means that when data changes in the model, it is reflected in the view immediately, and vice versa, making it easier for developers to manage state and user interfaces. Additionally, Angular utilizes a component-based architecture, enabling developers to create reusable components that encapsulate functionality and style, which enhances both maintainability and scalability of applications.

Another essential feature of Angular is its robust dependency injection system, which provides a way to manage and configure the services and components in an application. This promotes better code organization and testing, as components can easily request the services they depend on without needing to know the details of their instantiation. Furthermore, Angular offers a powerful routing module, allowing developers to create single-page applications (SPAs) that provide a smooth navigation experience for users through the use of URL manipulation. Understanding these core features will empower beginners to build efficient and modern web applications with Angular.

Optimizing your Angular applications is crucial for delivering a smooth user experience and improving performance. Here are 10 tips to help you enhance your Angular apps:

1. Use Lazy Loading: Implement lazy loading to load modules only when needed, reducing the initial load time of your application.
2. OnPush Change Detection: Utilize the OnPush strategy to minimize the amount of change detection Angular performs, enhancing performance in complex applications.
3. Track By in ngFor: Use the trackBy function in ngFor to help Angular identify items in lists and avoid unnecessary re-renders.
4. AOT Compilation: Enable Ahead-of-Time (AOT) compilation to reduce the size of the application bundle and improve load times.
5. Optimize Template Expressions: Keep expressions in templates simple and avoid complex logic to reduce the processing required during change detection.

In addition to the initial strategies, consider these further tips to ensure your Angular application runs efficiently:

6. Service Workers: Implement Service Workers to enable better caching and offline capabilities, improving the user experience during flaky network conditions.
7. Reduce Bundle Size: Use tools like Webpack and Tree Shaking to minimize the size of your application bundles, leading to faster load times.
8. Profile and Analyze: Regularly profile and analyze your application to identify bottlenecks using tools like Chrome DevTools.
9. Use TrackBy for ngFor: Optimize the rendering of lists in your templates by using TrackBy, which helps to speed up rendering by tracking items by their unique identifiers.
10. Code Splitting: Consider using code splitting to break down large bundles into smaller chunks, which can be loaded on demand.

Building scalable applications with Angular and RESTful APIs involves a well-planned architecture that can manage increasing loads. First, it's crucial to understand the principles of modularity in Angular. By implementing modules, components, and services effectively, you can isolate application features and ensure each part is manageable and reusable. Utilize Angular's HttpClient to communicate with your RESTful API, allowing seamless data exchange while maintaining performance. Consider adopting state management libraries like NgRx to help manage complex state changes efficiently, especially as your application grows.

Another essential aspect of building scalable applications is focusing on performance optimization. Utilize lazy loading to load modules only when they are required, which reduces the initial load time significantly. Additionally, take advantage of Angular's built-in tools for trackBy methods in ngFor loops to enhance rendering performance when displaying large lists. Lastly, ensure your RESTful APIs are designed to handle high throughput; effective caching strategies and pagination can alleviate server load. By following these best practices, your Angular applications can scale seamlessly to meet user demands.