What Happens When You Type www.google.com and Press Enter?
Published: 2023-10-13 15:22:23

Have you ever wondered what happens when you type www.google.com and press enter? 
It may seem like a simple process, but there are many steps involved in making this happen. In this article, we will take a closer look at the different components that come into play when you type a URL into your browser and press enter.

Without further ado, let's jump into it
 
The first thing that happens when you type www.google.com is that your browser sends a DNS (Domain Name System) request to a DNS server. Now, what is a DNS server ? How does it work ? Why do we need it ?

## 1. DNS Server

The DNS server is responsible for translating the domain name (www.google.com) into an IP address that your computer can understand. This is necessary because computers communicate with each other using IP addresses eg : `192.168.0.0` , not domain names. 

Once your browser has the IP address for www.google.com, it establishes a TCP (Transmission Control Protocol) connection with the server hosting the website. 

## 2. TCP/IP 
TCP is a protocol that ensures reliable communication between two devices over a network. It breaks data into packets and sends them across the network, reassembling them at the other end. 
 
## 3. Firewall 
Before the connection is established, your computer's firewall may check to see if the connection is allowed. A firewall is a security system that monitors and controls incoming and outgoing network traffic. If the firewall determines that the connection is not allowed, it will block the connection. 
 
## 4. HTTPS/SSL 
If the connection is allowed, your browser will attempt to establish an HTTPS (Hypertext Transfer Protocol Secure) connection with the web server. HTTPS is a secure version of HTTP, which is the protocol used to transfer data between your browser and the web server. HTTPS uses SSL (Secure Sockets Layer) or TLS (Transport Layer Security) to encrypt the data being sent between your browser and the web server. This ensures that the data cannot be intercepted and read by anyone who may be listening on the network. 
 
## 5. Load-Balancer 
Once the HTTPS connection is established, your request is sent to a load-balancer. A load-balancer is a device that distributes incoming network traffic across multiple servers. This is done to ensure that no single server becomes overloaded and that the website remains available to users. Load-balancers use various algorithms to determine which server should handle each request, such as round-robin, least connections, or IP hash. 
 
## 6. Web Server 
The load-balancer forwards your request to one of the web servers hosting the website. The web server is responsible for processing your request and generating a response. This response may include HTML, CSS, JavaScript, images, or other resources that make up the website. Web servers like Apache, Nginx, or Microsoft IIS handle the request and serve the appropriate files to your browser. 
 
## 7. Application Server 
If the website has dynamic content, your request may be forwarded to an application server. An application server is a server that runs applications that generate dynamic content. These applications may include server-side scripting languages like PHP, Python, or Java. The application server may interact with a database to retrieve data that is used to generate the response. 
 
## 8. Database 
If the application server needs to retrieve data from a database, it sends a request to the database server. The database server retrieves the requested data and sends it back to the application server, which uses it to generate the response. Databases like MySQL, PostgreSQL, or MongoDB are commonly used to store and retrieve data for dynamic websites. 
 
### Conclusion 
As you can see, there are many steps involved in the process of loading a website. From the DNS request to the database server, each component plays a crucial role in ensuring that the website is loaded quickly and reliably. Understanding how these components work together can help you troubleshoot issues when they arise and appreciate the complexity of the modern web. Next time you type www.google.com and press enter, you'll have a better understanding of the behind-the-scenes processes that make it all possible.