Event-Driven Architecture is a pivotal concept in Node.js that empowers developers to build scalable and high-performance applications. Unlike traditional request-response models, Node.js operates on an event loop, enabling it to handle numerous simultaneous connections with minimal overhead. This approach allows for non-blocking I/O operations, meaning that while a function is waiting for an operation to complete (like reading a file or querying a database), Node.js can continue executing other tasks. Consequently, this enhances the application's responsiveness, making it ideal for real-time applications such as chat servers or live streaming services.

In Node.js, events play a crucial role in driving the application's functionality. The EventEmitter class is at the core of this architecture, allowing objects to emit events and subscribe to them. For instance, a web server can emit a 'request' event whenever it receives a new request, and other parts of the application can listen for this event to respond appropriately. This event-driven model promotes a decoupled architecture, where different components can interact through events without being tightly integrated. As a result, developers can create more maintainable and flexible applications that can easily adapt to changing requirements.

Node.js has revolutionized the way developers approach server-side programming, enabling the creation of high-performance applications across various sectors. Its non-blocking, event-driven architecture makes it particularly well-suited for applications that require real-time interactions or handle numerous concurrent connections. Top 10 real-world applications built with Node.js showcase its versatility and robust capabilities, from social networking sites to collaborative tools.

1. Netflix: The streaming giant utilizes Node.js to deliver fast and efficient user experiences while managing loads of data.
2. LinkedIn: Leveraging Node.js, LinkedIn improved its mobile backend to handle an enormous number of connections.
3. PayPal: The payment platform transitioned to Node.js for its ability to build data-driven APIs and reduce response times.
4. Uber: This ride-sharing app uses Node.js to manage real-time data transmission, ensuring seamless connectivity.
5. Trello: The project management tool employs Node.js for its real-time updates, improving collaboration among users.
6. eBay: eBay's real-time auction functionality utilizes Node.js to improve performance and maintain high throughput.
7. Medium: The blogging platform benefits from Node.js' asynchronous capabilities to handle numerous users concurrently.
8. Walmart: The retail giant uses Node.js to manage its online infrastructure during peak shopping seasons.
9. NASA: NASA employs Node.js for its data management needs, capitalizing on its ability to handle large streams of data efficiently.
10. Yahoo!: Yahoo! leverages Node.js for its performance and scalability in real-time applications.

Getting started with Node.js can be an exciting journey for newcomers to web development. Node.js is a runtime environment that allows you to execute JavaScript on the server side, opening up a new world of possibilities for building scalable applications. To begin, the first thing you'll want to do is download and install Node.js from the official website. Once installed, you can verify the installation by running node -v in your command line, which should return the installed version number.

After installing Node.js, it's time to set up your first project. Start by creating a new directory for your project and navigate into it using your terminal. You can initialize a new Node.js project by running npm init. This command will guide you through creating a package.json file, which manages your project's dependencies and scripts. Finally, create an index.js file, where you can write your first Node.js application. For instance, a simple server can be set up using:

const http = require('http');
const server = http.createServer((req, res) => {
  res.statusCode = 200;
  res.setHeader('Content-Type', 'text/plain');
  res.end('Hello World!');
});
server.listen(3000, () => {
  console.log('Server running at http://localhost:3000/');
});

This code initializes a basic web server that listens on port 3000, allowing you to test your setup.