What happens when you type google.com in your browser and press Enter?

Have you ever wondered what goes on behind the scenes when you type https://www.google.com into your browser's address bar and press Enter? The process might seem instantaneous, but in reality, it involves a complex chain of events that allows you to access the web seamlessly. In this blog post, we will take a closer look at the journey of a simple web request, covering key components like DNS, TCP/IP, firewalls, HTTPS/SSL, load balancers, web servers, application servers, and databases.

DNS Request: The process begins with a Domain Name System (DNS) request. When you type www.google.com into your browser, it first needs to resolve the human-readable domain name to an IP address that computers understand. Your browser contacts a DNS server, which translates the domain name into an IP address (e.g. 54.207.112.20). This mapping allows your browser to locate the destination server on the internet.

TCP/IP: Once your browser knows the IP address of the web server hosting www.google.com, it establishes a connection using the Transmission Control Protocol (TCP) and Internet Protocol (IP). TCP ensures reliable communication by breaking data into packets, sending them, and ensuring they are received and reassembled in the correct order.

Firewall: Before your request reaches the web server, it might pass through a firewall. Firewalls are security devices that filter incoming and outgoing traffic to protect a network from malicious activity. They can block or allow traffic based on predefined rules.

HTTPS/SSL: In the case of Google, you'll notice the https in the URL. This means your connection is secured with Hypertext Transfer Protocol Secure (HTTPS), which uses Secure Sockets Layer (SSL) or Transport Layer Security (TLS) to encrypt data exchanged between your browser and the server. This encryption ensures your data is safe from eavesdropping.

Load-Balancer: High-traffic websites like Google often employ load balancers. Load balancers distribute incoming requests across multiple servers to ensure even resource utilization and prevent overloading any single server. This improves performance and redundancy.

Web Server: The load balancer directs your request to one of Google's many web servers. The web server is responsible for processing HTTP requests, handling user authentication, and serving web pages. It retrieves the requested page or performs a search operation, as in Google's case.

Application Server: In some cases, like when you submit a search query, the web server communicates with an application server. The application server runs the back-end code, processes the request, and generates the dynamic content. For Google, this could involve complex algorithms for search ranking.

Database: To retrieve personalized information or search results, the application server often needs to fetch data from a database. The database contains vast amounts of information, and it's being queried for the specific data you requested. In Google's case, it could be search results, ads, and others.

As your requested data traverses this intricate network of components, it's rapidly assembled and encrypted, making its way back through the load balancer and back to your browser. Your browser then decrypts and renders the page, presenting the familiar Google search interface or any other webpage you've requested.

The entire process, from typing https://www.google.com to seeing the search results, happens in a fraction of a second, thanks to the seamless orchestration of these crucial components. Understanding this process can give you a deeper appreciation for the technological marvel that is the World Wide Web.