Web server vs application server has been a common debate in IT teams for years. However, most of the time these terms are used interchangeably, which is not really right. Many enterprise teams use both, and understanding the use cases will help them get the most out of it.
This guide talks about the difference between the two with examples, useful tables, and use cases.
But first, let’s talk about each separately.
What is a Web Server?
A web server is a system that delivers web content in the form of web pages to its users. It is the one responsible to load, store, process, and serve files that make up a webpage or an application. In a nutshell, a web server processes the incoming query from the user and produces an output, such as an HTML page, dynamic media, or images.
A web server is responsible for:
- Handling HTTP Requests: when a user enters a specific query in the form of a URL, the browser would essentially send an HTTP request for a specific file. The web server responds with the requested file in the form of an HTML document.
- Serving static content: A web server usually responds with a static file such as images, videos, and style sheets.
- Handling dynamic content: Web servers are usually custom configured to serve dynamic content by working with server-side scripting languages, such as PHP and Python.
- Routing requests: web servers process and manage routing requests by sending them to the corresponding resources.
- Logging: Web servers are configured to log in every request that they receive with time stamps, IP address, and status of request.
What is an Application Server?
An application server is a software framework that provides the environment for managing web applications. It hosts the server-side software components that help complex business logic, data processing, and interactions that are beyond a web server.
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While a web server is the one looking after static content, an application server is the one supporting backend infrastructure to bring out the data-driven, dynamic, and transactional content.
Key functions of an application server include:
- Business logic execution: application servers execute the core logic of web pages such as processing user input, database queries, calculations, important transactions, and more. This server acts as a bridge between user and backend services.
- Database connectivity: an application server usually has pre-built features for database connectivity, making it easy to manage data storage and retrieval.
- Session management: application servers manage user sessions to maintain state across multiple requests.
- Security: application servers are responsible for security features, such as authentication, encryption, data protection, and authorization.
- Middleware: Application servers are middleware between front-end application and backend system.
- Transaction handling: application servers can handle distributed transactions ensuring reliability and data consistency.
Web Server vs Application Server: Key Differences
To understand the core difference between an application server vs web server, let’s refer to this cheat sheet.
| Feature | Web Server | Application Server |
| Primary Purpose | Serves static content (HTML, images, CSS, etc.) | Hosts and runs dynamic content (business logic, databases) |
| Main Responsibility | Handles HTTP requests and serves static files | Runs applications, executes business logic, and manages sessions |
| Content Served | Static content (HTML, CSS, JavaScript, images) | Dynamic content (generated by business logic, database queries) |
| Protocol | Primarily uses HTTP (or HTTPS) | Supports HTTP, but also other protocols like JMS, RMI, SOAP, REST |
| Interaction with Database | Typically does not interact directly with a database | Handles database interactions for dynamic data processing |
| Examples | Apache HTTP Server, Nginx, Microsoft IIS | Apache Tomcat, WildFly (JBoss), GlassFish, Node.js, ASP.NET |
| Handling Dynamic Content | Limited; can forward requests to an application server | Full support for dynamic content generation (via server-side scripting) |
| Session Management | Basic session handling (via cookies or URL) | Advanced session management and user state handling |
| Business Logic | Does not handle business logic directly | Hosts and executes business logic and complex processing |
| Transaction Management | Typically does not support transaction management | Supports distributed transaction management for complex applications |
| Middleware | Does not provide middleware functionality | Often acts as middleware to facilitate communication between client and back-end systems |
| Security | Basic security features like SSL/TLS encryption | Advanced security features (e.g., authentication, authorization, encryption) |
| Use Case | Used for serving websites with static content | Used for applications requiring business logic, data processing, or enterprise services |
| Performance | Optimized for serving static content quickly | Optimized for running and managing complex applications and dynamic content |
Application vs Web Server in Practical Scenarios
In practicality, web servers and application servers play a complementary role in processing successful websites. Here are a few use cases to better understand the dynamics behind the two.
1. A static one page website
A static one-page website like a coming soon page only requires a web server, since it would only display text and media. No backend processing is required, therefore, no need for an application server.
2. An ecommerce website
An ecommerce website mainly requires an application server to handle the dynamic processing such as business logic, database processing, inventory management, pricing calculations, and more.
3. Web applications with RESTful APIs
This is a slightly complex situation, in such case scenarios, both application server and web server work together to process a query. Web server looks after the static components of the single page and the application server handles API requests.
Popular Web and Application Servers
Here are a few popular web and application servers for better understanding.
Popular Web Servers:
Servers static content and supports dynamic content modules. Most commonly used with hosting websites and CMS.
Most commonly used with high-traffic websites.
Used for hosting .NET applications, SharePoint, and enterprise services.
Used for high-performance websites since it is fast and scalable.
Popular Application Servers:
Most commonly used for Java web applications and Spring Boot apps.
It uses Full Java EE (Jakarta EE) server for enterprise apps and is used for large-scale enterprise applications.
Most commonly used for Java EE-based enterprise applications.
Most commonly used for APIs, and real-time apps (chat, notifications).
Most commonly used for modern web apps, APIs, and microservices.
Application servers and web servers often work together in a multi-tiered architecture to deliver web applications efficiently. Each server plays a distinct role in handling user requests and processing data. Here’s how they collaborate:
How do application servers and web servers work together?
Here is how application servers and web servers work together.
1. Client sends a request to the web server
A user sends a request through a URL to the web server. The web server receives this request and determines whether it can be fulfilled.
2. Handling static vs dynamic content
If the request is for static content such as an image, the web server will respond directly. If the request is for dynamic processing, such as fetching an entity from the database, the request is forwarded to the application server.
3. Processing by the application server
The application server then executes the required business logic. Such as a database query or data processing and the result is sent back in the form of HTML page.
4. Response sent to the client
The web server formats the response and sends it back to the user.
Wrapping Up – Web Server Vs Application Server
In the modern web development environment, both web and application servers play an important part for efficient, scalable, and secure query processing. However, implementing the right servers is an essential part of setting up a website so that users can experience smooth and seamless processing.
While web servers are the best for static and simple components, application servers are crucial for complex backend processing.
Frequently Asked Questions
1. Which server should I use for high-traffic website?
For high traffic processing, Nginx or Litespeed are the two top contenders due to their ability to handle large data effectively.
2. Is it possible to use both application servers and web servers together?
Yes, in most architectures web servers and application servers work together harmoniously. The web server handles incoming HTTP requests and servers static content and the application server handles dynamic content.
3. Can a web server work as an application server?
Some web servers (like Apache HTTP Server with PHP or Nginx with reverse proxying) can handle dynamic content. However, they do not provide the full range of features found in dedicated application servers.
