DNS Request:
Your browser first initiates a Domain Name System (DNS) request to resolve the human-friendly URL (www.google.com) into an IP address.
DNS servers worldwide work collaboratively to map the domain name to its corresponding IP address.
2. TCP/IP Handshake:
Once the IP address is obtained, your browser establishes a Transmission Control Protocol (TCP) connection to the destination server.
The Internet Protocol (IP) then routes your request through a series of routers to reach Google’s servers.
3. Firewall Check:
Upon reaching Google’s infrastructure, your request encounters a firewall, which acts as a security barrier.
The firewall evaluates the request to ensure it complies with security policies before allowing it further.
4. HTTPS/SSL Encryption:
If the website uses HTTPS (Hypertext Transfer Protocol Secure), as Google does, an SSL/TLS (Secure Sockets Layer/Transport Layer Security) handshake takes place.
This handshake ensures a secure and encrypted connection between your browser and Google’s servers, protecting your data from eavesdropping.
5. Load-Balancer Distribution:
Google, being a massive service, employs load balancers to distribute incoming requests efficiently among its numerous servers.
The load balancer selects an available server to handle your request, ensuring optimal performance and high availability.
6. Web Server:
The selected web server at Google receives your request and processes it.
It may involve handling static assets, such as HTML, CSS, and JavaScript, or routing your request to an application server for dynamic content.
7. Application Server:
For dynamic web pages or web applications, the application server comes into play.
It processes your request, interacts with databases, and generates the content you see on your screen.
8. Database Interaction:
If your request requires data retrieval or storage, the application server communicates with the backend databases.
The database server retrieves the necessary information and sends it back to the application server.
Finally, the processed data is sent back through the same channels, encrypted with HTTPS, and displayed on your browser as the Google homepage.