Web Server: Functions, Architecture and Types

Last Updated on August 17, 2023 by Mayank Dham

In the modern era, the internet has evolved into an essential component of virtually every facet of our existence. It serves as a tool for communication, leisure, learning, and even commerce. Supporting each website we explore is a web server responsible for transmitting the site’s content to our devices.

What is Web Server?

A web server functions as a computer system responsible for storing, handling, and disseminating website files to web browsers. Comprising both hardware and software components, web servers utilize the Hypertext Transfer Protocol (HTTP) to address queries initiated by internet users through the World Wide Web. Through this mechanism, web servers retrieve and dispatch the desired webpage to the user’s browser, like Google Chrome. Additionally, for managing files intended for email or storage purposes, web servers utilize the Simple Mail Transfer Protocol (SMTP) and the File Transfer Protocol (FTP).

So, what is web server made up of? On the hardware side, a web server connects to the internet, allowing it to share data or files with other devices that are also connected. This data can take many different forms, like HTML files, images, JavaScript files, and CSS stylesheets. Web server hardware contains web server software as well.

Web server software governs how web users access hosted files. It is made up of several parts, one of which is an HTTP server. An HTTP server is a piece of software that understands HTTP queries and URLs.

Functions of a Web Server

The functions of a web server can be broken down into several categories:

1. Storing and delivering web content:
   The primary function of a web server is to store and deliver web content such as web pages, images, videos, and other files to clients that request them. This involves processing incoming requests, retrieving the requested content from the server’s storage devices, and sending the content back to the client in the form of an HTTP response.

2. Handling HTTP requests:
   A web server handles HTTP (Hypertext Transfer Protocol) requests from clients or users. The HTTP protocol is the standard protocol used for communication between web servers and clients. When a client requests a web page or other web content, the request is sent to the web server over the internet. The web server then processes the request, retrieves the requested content from its storage devices, and sends it back to the client in the form of an HTTP response.

3. Generating responses to HTTP requests:
   A web server generates responses to HTTP requests by running web applications that generate dynamic content based on user input and other factors. For example, an e-commerce website may use a web application to generate web pages dynamically that display product information, pricing, and availability based on user searches or selections.

4. Managing and maintaining web applications:
   A web server manages and maintains web applications that provide various services such as e-commerce, social networking, and content management. This involves installing, configuring, and updating web application software, monitoring performance, and troubleshooting issues that may arise.

5. Supporting multiple clients simultaneously:
   A web server supports multiple clients or users simultaneously by handling multiple HTTP requests at the same time. This is achieved through the use of multi-threading or other techniques that allow the server to process requests in parallel.

What is Web Server Architecture?

A Web server architecture establishes the arrangement, elements, and setups that are essential for its effective operation and the provision of web-oriented services to users. This constitutes a pivotal facet of web server administration, exerting substantial influence over the server’s performance, dependability, and safeguarding.

The two main approaches to web server architecture are the concurrent approach and the single-process-event-driven approach.

1. Concurrent Approach:
   In the concurrent approach, the web server creates a separate process or thread for each client request. Each process or thread handles one request at a time, allowing multiple requests to be processed simultaneously.

   For example, suppose a web server receives five client requests simultaneously. In the concurrent approach, the server will create five separate processes or threads to handle each request concurrently. This approach is often used in traditional web servers like Apache, which can handle a large number of concurrent connections.

2. Single-Process-Event-Driven Approach:
   In the single-process-event-driven approach, the web server uses a single process or thread to handle all client requests. The server waits for events (e.g., new connection requests, and incoming data) and handles them one at a time in a non-blocking manner.

   For example, suppose a web server receives five client requests simultaneously. In the single-process-event-driven approach, the server will use a single process or thread to handle all five requests one at a time, in a non-blocking manner. This approach is often used in modern web servers like Node.js, which are designed to handle large numbers of lightweight connections efficiently.

Types of Web Servers

Here are some of the most common types of web servers:

1. Apache HTTP Server:
   Apache HTTP Server is an open-source web server software that is widely used around the world. It is known for its high performance, stability, and flexibility, and supports a wide range of operating systems, including Linux, Windows, and macOS.

2. Microsoft Internet Information Services (IIS):
   IIS is a web server software developed by Microsoft that is designed to run on Windows operating systems. It is known for its scalability, security features, and support for Microsoft technologies such as ASP.NET and Microsoft SQL Server.

3. Nginx:
   Nginx is a high-performance, open-source web server software that is known for its speed, scalability, and ease of use. It is often used as a reverse proxy server or load balancer and can be used to serve static and dynamic content.

4. Lighttpd:
   Lighttpd is a lightweight, open-source web server software that is designed for high performance and low resource consumption. It is known for its speed, stability, and security features.

How Does a Web Server Work?

Here’s a basic overview of how a web server works:

1. The client device (e.g., a web browser) sends a request to the web server for a particular resource, such as a web page.
2. The web server receives the request and processes it, checking if the requested resource exists and is accessible.
3. If the resource is available, the web server retrieves it and sends it back to the client’s device as a response.
4. The client device receives the response and displays the resource (e.g., web page) to the user.

This process typically involves several layers of communication protocols, including HTTP (Hypertext Transfer Protocol), TCP/IP (Transmission Control Protocol/Internet Protocol), and DNS (Domain Name System).

Web servers can also perform other functions such as database management, session management, and security checks to ensure that the requested resources are delivered securely and efficiently.

Static Web Server vs Dynamic Web Server

Static and dynamic web servers are two types of web servers that differ in how they deliver web content.

Static web servers serve pre-existing web pages that do not change in real-time. These web pages are usually written in HTML and CSS and are stored on the web server’s file system. Whenever a client device requests a page, the web server retrieves the requested file and sends it back to the client as a response.

Dynamic web servers, on the other hand, generate web pages on the fly in response to user requests. These servers use programming languages like PHP, Python, and Ruby to build web pages from databases, APIs, and other sources of dynamic data. Whenever a client device requests a page, the server runs the necessary code to generate the page and sends it back to the client as a response.

Uses of Web Server

Web servers have a wide range of uses and applications, as they are the backbone of the internet and the means by which web resources are delivered to users. Here are some of the most common uses of web servers:

1. Hosting websites: Web servers are used to host websites, making them accessible to users around the world. They serve up HTML, CSS, JavaScript, and other web resources that make up web pages.
2. Running web applications: Web servers are used to host web applications that run in the browser, such as online shopping carts, social media platforms, and productivity tools.
3. Streaming media: Web servers are used to stream audio and video content over the internet, allowing users to access music, movies, and other multimedia resources.
4. Managing online databases: Web servers are used to manage online databases, allowing users to access and manipulate data via web-based interfaces.
5. Cloud computing: Web servers are used to power cloud computing services, allowing users to access computing resources and data storage via the Internet.
6. Internet of Things (IoT): Web servers are used to power IoT devices, allowing them to communicate and exchange data over the Internet.
7. File sharing: Web servers are used to share files over the internet, allowing users to access and download files such as documents, images, and videos.

What is Web Server Security?

Web server security refers to the measures and practices used to protect a web server from unauthorized access, malicious attacks, and other security threats. A secure web server ensures that sensitive data and resources are protected from unauthorized access, ensuring the confidentiality, integrity, and availability of web resources.

Here are some common web server security measures:

1. Regular software updates: It’s important to keep the web server software and applications up-to-date to address any security vulnerabilities or bugs.
2. Secure configuration: The web server should be configured with strong security settings, such as secure file permissions, SSL/TLS encryption, and secure authentication mechanisms.
3. Access control: The web server should be configured to restrict access to sensitive data and resources, including password-protecting directories and using firewall rules.
4. Security testing: Regular security testing and vulnerability scanning should be performed to identify and address any potential security threats.
5. Monitoring and logging: Monitoring the web server logs and activity can help detect and respond to security incidents in a timely manner.
6. Backup and recovery: Regular backups of the web server and data should be performed to ensure quick recovery in case of data loss or other security incidents.

Conclusion
To sum up, web server architecture constitutes a fundamental element of the internet infrastructure, facilitating the dissemination of web content and applications. Their pivotal function involves ensuring widespread access to information and services for a global user base. Grasping the operations, structure, and safeguarding of web servers holds immense importance for web developers, IT experts, and anyone intrigued by the inner workings of the online realm.

FAQs

Here are some frequently asked questions (FAQs) on a web server.

Q1: What is the difference between a static and dynamic web server?
Ans: A static web server serves pre-existing web pages that do not change in real time, while a dynamic web server generates web pages on the fly in response to user requests.

Q2: How can I improve the performance of my web server?
Ans: Some ways to improve the performance of a web server include optimizing code and web resources, implementing caching, and using load balancing.

Q3: What is web server log file?
Ans: A web server log file is a record of all requests made to a web server, including the IP address of the requester, the requested resource, and the response status.

Q4: What is web server certificate?
Ans: A web server certificate is a digital certificate that verifies the identity of a web server and encrypts data transmitted between the server and client devices.

Q5: Can I run multiple web servers on the same machine?
Ans: Yes, it is possible to run multiple web servers on the same machine, as long as they are configured to listen on different ports or IP addresses.

Q6: What is the default port for HTTP requests?
Ans: The default port for HTTP requests is port 80.

Q7: What is web server API?
Ans: A web server API (Application Programming Interface) is a set of protocols and tools that developers use to interact with a web server and build web applications.