Web Server vs. Application Server:
Web Server:
- Functionality: Primarily handles HTTP requests and responses. It serves static content such as HTML, CSS, and images to clients (browsers).
- Use Cases: Handles the delivery of static content and simple request/response processing (e.g., basic authentication, URL redirection).
- Examples: Apache HTTP Server, Nginx, Microsoft IIS (which can also serve as an application server in certain scenarios).
Application Server:
- Functionality: Executes business logic, handles dynamic content generation, and processes application-specific logic. Communicates with databases, messaging systems, and other resources.
- Use Cases: Processes dynamic content, manages business logic, and interacts with various backend services.
- Examples: Apache Tomcat, WildFly (formerly JBoss), Microsoft ASP.NET, Ruby on Rails (which includes its own application server, e.g., Puma or Unicorn).
Is IIS (Internet Information Services) is a web server or app server?
- IIS is primarily a web server developed by Microsoft.
- It can also serve as an application server when hosting applications built with technologies like ASP.NET.
- IIS handles HTTP requests and can execute server-side code to generate dynamic content, making it both a web server and an application server depending on the context.
Real-Time Examples of Web server & App Server
Web Server Examples:
- Nginx: Widely used as a web server and reverse proxy server.
- Apache HTTP Server: One of the most popular web servers, serving static content and handling dynamic content via modules.
- Microsoft IIS: Primarily a web server but can also host ASP.NET applications, providing a platform for executing server-side code.
Application Server Examples:
- Apache Tomcat: Used for deploying Java-based web applications with servlets and JSP.
- WildFly (formerly JBoss): A Java EE application server supporting various Java technologies.
- Microsoft ASP.NET: When hosted on IIS, ASP.NET applications leverage IIS as both a web server and an application server.
In real-world scenarios, a combination of web servers and application servers is often used. Web servers handle static content and may serve as reverse proxies, forwarding dynamic requests to application servers. This separation allows for better scalability, maintainability, and the ability to use specialized servers for specific tasks.