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

We’ve all done it countless times — you type a URL like “https://www.google.com" into your web browser, hit Enter, and voila, Google’s homepage appears. But what’s happening behind the scenes?

In this blog post, we’ll take you on a journey through the various layers of the web stack to understand the intricate process that occurs when you initiate this seemingly simple action.

DNS Request

When you enter a URL like “https://www.google.com" in your browser’s address bar, your computer needs to find the IP address associated with that domain name. The first step is a DNS (Domain Name System) request. Think of DNS as the internet’s address book; it maps human-friendly domain names to their corresponding IP addresses, allowing machines to locate each other on the internet. This step enables your browser to know where to send the request.

TCP/IP

Armed with the IP address, your browser initiates a connection using the Transmission Control Protocol (TCP) and Internet Protocol (IP). TCP/IP is a suite of protocols governing how data is transmitted and received over the internet. It ensures that data packets reach their intended destination intact and in the correct order, with multiple layers each playing a specific role in data transmission. Here’s how it works:

• Data is broken into packets.
• Routing and addressing occur at the Internet Layer (IP).
• The Transport Layer establishes a connection, monitors data flow, and reassembles packets at the receiving end.

Firewall

Firewalls are critical for network security, acting as barriers between your internal network and the external world, typically the internet. They examine incoming and outgoing traffic to decide whether to allow or block data packets. Your request may pass through one or more firewalls, essential for protecting the network from unauthorized access.

HTTPS/SSL

Security is paramount in web browsing. HTTPS and SSL ensure secure internet communication, especially for transmitting sensitive data. They provide encryption and authentication mechanisms to protect data during transmission. The “https” in the URL indicates a secure connection. When your browser communicates with the server, it engages in the Secure Sockets Layer (SSL) handshake, ensuring private and secure communication.

Load Balancer

High-traffic websites like Google need to handle massive loads efficiently. Load balancers distribute incoming requests across multiple servers, preventing any single server from becoming overwhelmed. This mechanism enhances performance, scalability, and reliability:

• Traffic is evenly distributed.
• Health monitoring ensures responsiveness.
• Session persistence ensures a consistent user experience.
• Scalability accommodates changing traffic levels.

Web Server

After the load balancer determines the appropriate server to handle your request, it forwards it to a web server. The web server processes your request, which may involve fetching and rendering web pages or executing application logic. For Google, it means returning the search results page.

Application Server

Web applications often have a multi-tier architecture. The application server handles business logic, manages user sessions, interacts with databases, and more. In Google’s case, the application server processes search queries and returns results.

Database

To provide dynamic content and personalized information, web applications rely on databases. The application server communicates with the database to fetch or update data, such as user profiles or search results. For Google, your search query accesses a vast database of indexed web pages.

The seemingly simple act of typing “https://www.google.com" into your browser’s address bar and pressing Enter initiates a complex journey through the layers of the web stack. Each component, from DNS requests to load balancers, web servers, application servers, and databases, plays a crucial role in delivering the web page you see on your screen. Understanding this process is key to appreciating the intricacies of how the internet works.