A web server is a computer program that stores, processes, and delivers web content to users. It’s essentially the backbone of the internet, acting as a middleman between your web browser and the website you want to visit. The term “web server” can refer to both the hardware (the physical computer) and the software that runs on it.

When you type a website address (URL) into your browser, you’re initiating a request. This request travels across the internet to the correct web server. Once the server receives the request, the software on the server finds the requested files—like HTML documents, images, and videos—and sends them back to your browser. Your browser then takes these files and assembles them into the webpage you see.

How Web Servers Work

The process of a web server delivering a page can be broken down into a few key steps:

1. Request: You enter a URL like www.example.com into your browser. The browser then finds the IP address associated with that domain name using a system called DNS (Domain Name System), which is like an address book for the internet.
2. Communication: Your browser sends a request to the web server’s IP address using HTTP (Hypertext Transfer Protocol). This is the standard language that web browsers and servers use to communicate.
3. Processing: The web server receives the request and, in most cases, processes it. This can be as simple as finding a static file and sending it back, or it can be more complex, involving running a script to generate dynamic content, like a personalized welcome message or a list of products from a database.
4. Response: The web server sends a response back to your browser. If everything goes well, it will include the requested files. If something goes wrong, like a page that doesn’t exist, it will send an error message, such as the famous “404 Not Found.”

Static vs. Dynamic Web Servers

Web servers can be categorized as either static or dynamic, depending on the content they serve.

• Static Web Server: This type of server simply delivers files “as-is” without any changes. It consists of the hardware and a basic HTTP server. It’s used for websites with content that doesn’t change, like a simple personal portfolio page with no user interaction.
• Dynamic Web Server: A dynamic server includes a static server plus additional software, such as an application server and a database. This allows it to generate content on the fly based on user input or other factors. For example, a social media feed or an e-commerce shopping cart is handled by a dynamic web server, as the content is unique to each user and constantly changing.

Web servers are a foundational part of web development. Understanding how they work is crucial, whether you are building a simple website or a complex web application. Popular web server software includes Apache, Nginx, and Microsoft IIS.