The internet, with its vast array of websites and applications, plays a crucial role in our lives. But how does it all work behind the scenes? This article delves into the essential components that power this digital world: applications, servers, and application servers.

1. Applications: The Heart of Functionality

Think of applications (apps) as the software programs that fulfill specific functionalities. They can be web-based, accessible through a browser, or mobile apps, downloaded and installed on your smartphone or tablet. These apps cater to various needs, from communication (e.g., email, messaging) and entertainment (e.g., music streaming, video games) to productivity (e.g., document editing, project management) and e-commerce (e.g., online shopping).

2. Servers: The Powerhouse Behind the Scenes

Servers act as the central computing systems that store and process data for applications. Imagine them as powerful computers specifically designed to handle high volumes of requests and data transfers. They run various software programs, including operating systems, databases, and web servers, to keep applications functioning smoothly.

3. Application Servers: The Orchestrators of Dynamic Content

While servers provide the foundation, application servers act as specialized software that hosts and manages applications. They play a crucial role in generating dynamic content, which is content that changes based on user input or other factors. Here’s how they work:

  • Receive requests: When a user interacts with an application, the request is first sent to a web server.
  • Delegate tasks: If the request requires dynamic content generation, the web server forwards it to the application server.
  • Process application logic: The application server interprets the request and executes the necessary application code, often referred to as business logic. This code may involve:
    • Accessing databases to retrieve or update information.
    • Performing calculations or computations.
    • Integrating with other systems or services.
  • Generate response: Finally, the application server generates the appropriate response based on the processed data and sends it back to the web server.
  • Deliver content: The web server then delivers the response to the user’s device, such as a web browser or mobile app.

Key benefits of using application servers:

  • Improved performance: By handling dynamic content generation separately, application servers can optimize web server performance and handle more user requests simultaneously.
  • Scalability: They can be easily scaled up or down to meet the changing demands of an application.
  • Security: Application servers often provide additional security features to protect sensitive data and prevent unauthorized access.
  • Developer focus: By handling complex tasks, they allow developers to focus on the core functionality of the application.

Now, let’s delve deeper into some popular Java EE Servers:

  • GlassFish Server: An open-source application server developed by Oracle. It’s lightweight, flexible, and easy to use, making it a popular choice for small and medium-sized businesses.
  • IBM WebSphere Application Server: A comprehensive and powerful application server from IBM. It’s known for its scalability, security, and support for various Java EE specifications.
  • Oracle WebLogic Server: A commercial application server offering robust features and enterprise-grade scalability. It’s well-suited for large and complex applications.
  • Red Hat JBoss EAP (Enterprise Application Platform): A full-featured application server platform from Red Hat, built on the popular JBoss open-source project. It provides a reliable and scalable foundation for mission-critical applications.
  • Tomcat: A free and open-source web server, but not strictly a Java EE server. However, it can be extended with additional components to support Java EE features. It’s known for its simplicity and performance, making it a popular choice for smaller applications or development environments.

Beyond Java EE: Exploring the Diverse Landscape of Application Servers

We explored the world of Java EE servers. Now, let’s venture outside this realm and discover the rich ecosystem of application servers available for different technologies and needs.

Node.js Servers:

  • Express.js: A popular, minimalist web framework built on Node.js, offering flexibility and a robust set of features for building web applications and APIs.
  • Koa.js: Another popular web framework for Node.js, known for its smaller footprint and flexibility compared to Express.js. It allows for finer-grained control over the request-response cycle.
  • NestJS: A relatively new but powerful framework for building scalable, enterprise-grade Node.js applications inspired by Angular. It provides a structured, layered architecture and simplifies development.

Non-Java Servers:

  • Apache HTTP Server: A free and open-source web server, prevalent on the internet. While not strictly an application server, it can be extended with modules to support various functionalities beyond basic static content serving.
  • Microsoft IIS (Internet Information Services): A web server included with Microsoft Windows Server operating systems. It offers various features for hosting web applications and APIs, though primarily caters to the Windows ecosystem.
  • Nginx (pronounced “engine-x”): A high-performance, open-source web server known for its efficiency and scalability. It’s often used as a reverse proxy or load balancer in front of application servers.

Python Servers:

  • Django Channels: An asynchronous framework built on top of the Django web framework, enabling real-time features like chat or websockets.
  • Gunicorn: A popular Python web server gateway interface (WSGI) server, often used for deploying Python web applications.
  • uWSGI: Another WSGI server for Python, known for its flexibility and advanced features.

Specialized Servers:

  • PHP Servers:
    • HHVM (HipHop Virtual Machine): A high-performance, open-source runtime environment for running PHP code, offering significant performance improvements over traditional PHP interpreters.
    • Phalcon: A high-performance PHP framework that optimizes performance and reduces code complexity.
    • Zend Server: A commercial PHP application server offering a comprehensive platform for building, deploying, and managing PHP applications.

The landscape of application servers is vast and ever-evolving, offering a variety of options for building and deploying web applications. Whether you’re using Java, Node.js, Python, PHP, or another language, there’s a server well-suited to your project’s specific needs.


  • Consider your programming language: Different servers cater to different languages; choose one compatible with your development environment.
  • Evaluate your project’s scale: Determine your application’s expected traffic and growth to select a server that can handle the load.
  • Prioritize desired features: Consider essential functionalities, such as security, scalability, and ease of use, when making your choice.

Exploring the various options and understanding their strengths and weaknesses is crucial for making informed decisions. By delving deeper into this dynamic world of application servers, you can empower yourself to build robust, efficient, and scalable web applications.

Feel free to share your experiences and preferences when it comes to application servers in the comments below!