The Journey of a Web Request: Exploring the Web Stack

Introduction: Have you ever wondered what happens behind the scenes when you type a URL in your browser and hit enter? The seemingly simple action sets off a series of intricate processes that involve various components of the web stack. In this article, we'll explore the journey of a web request, focusing on the steps involved from typing "" to the moment you see Google's search page.

  1. DNS Request: When you type "" in your browser, the first step is a DNS (Domain Name System) request. Your browser needs to convert the human-readable domain name ( into an IP address that identifies the server hosting the website. It sends a DNS query to a DNS resolver, such as your ISP's DNS server or a public DNS service like Google DNS. The resolver looks up the IP address associated with the domain name and returns it to your browser.

  2. TCP/IP: Armed with the IP address obtained from the DNS resolution, your browser establishes a TCP/IP (Transmission Control Protocol/Internet Protocol) connection with the server hosting TCP ensures reliable data transmission by breaking the information into small packets, managing their delivery, and reassembling them at the destination.

  3. Firewall: Once the TCP/IP connection is established, the web request may encounter a firewall. Firewalls are security mechanisms that monitor and control incoming and outgoing network traffic based on predefined rules. They serve to protect the network and systems from unauthorized access and potential threats. If the request passes through the firewall successfully, it proceeds to the next step.

  4. HTTPS/SSL: In the case of "https://" (Hypertext Transfer Protocol Secure), an additional layer of security comes into play. HTTPS employs SSL (Secure Sockets Layer) or its successor, TLS (Transport Layer Security), to encrypt the data exchanged between the browser and the web server. This encryption ensures that the communication remains confidential and protected from eavesdropping or tampering.

  5. Load-Balancer: For popular websites like Google, a load-balancer often comes into action to distribute incoming requests across multiple servers. Load-balancers help optimize performance, enhance reliability, and prevent any single server from being overwhelmed. They intelligently route requests to the most available or least busy servers, ensuring an even distribution of traffic.

  6. Web Server: After passing through the load-balancer (if present), the web request reaches one of the web servers hosting the website. The web server is responsible for handling the request, retrieving the requested resources, such as HTML, CSS, JavaScript, or images, and generating an appropriate response. The response typically contains the requested web page's content and metadata.

  7. Application Server: In more complex web applications, an application server may come into play. It acts as an intermediary between the web server and the backend services or databases. The application server executes the application's business logic, processes user inputs, interacts with databases, and generates dynamic content to be included in the response sent back to the web server.

  8. Database: If the web application relies on a database to store and retrieve data, the application server communicates with the database server. It may query the database for information, update records, or perform other operations necessary to fulfill the user's request. The database server processes these requests and sends back the requested data to the application server, which ultimately includes it in the response to the web server.

Conclusion: The journey of a web request, from typing a URL in your browser to the final display of the requested page, involves a series of interconnected components within the web stack. Understanding how DNS resolution, TCP/IP, firewalls, HTTPS/SSL, load-balancers,