What happens when you type `https://www.google.com` in your browser and press Enter.

Introduction

Are you curious about what happens behind the scenes when you type a website address into your browser and hit Enter? It may seem like a simple process, but there's actually a lot going on under the hood to ensure that you can access your favorite websites. In this blog post, I am going to take a deep dive into the steps that occur when you type `https://www.google.com` in your browser and press Enter. From DNS requests to databases, we'll cover everything you need to know to better understand the inner workings of the internet. So buckle up and get ready to explore the complex world of web browsing!

Web browsers

To begin with let’s have a look at what a web browser is. What's a web browser?A web browser is like a magic wand that lets you explore the endless universe of the internet. It's a software program that helps you access websites, videos, images, and other online content. When you type "https://www.google.com" into your browser's address bar, it sends a request to Google's servers asking for the website's content. The browser then receives the website's code and uses it to display the site's layout, text, and images on your screen. Essentially, the web browser acts as your gateway to the internet, helping you navigate the vast and exciting digital world.

There are several web browsers available today, each with its own unique features and capabilities. Some of the most popular web browsers include:

● Google Chrome: Developed by Google, Chrome is known for its fast performance, user-friendly interface, and extensive range of extensions.

● Mozilla Firefox: An open-source browser that is highly customizable and prioritizes user privacy.

● Apple Safari: The default browser for Apple devices, Safari is known for its speed and efficiency, as well as its integration with other Apple products.

● Microsoft Edge: The successor to Internet Explorer, Edge is a modern browser that offers fast browsing speeds and integration with Microsoft services.

● Opera: A feature-rich browser that includes a built-in VPN, ad blocker, and other useful tools.No matter which browser you choose, they all play a vital role in helping you access and explore the internet.

DNS Request

Now let's dive into the core steps our url takes in order to render the google search page we get in return when we type ‘https://www.google.com’. The first step in this process is the DNS request, which is like a phone book for the internet. DNS, or Domain Name System, is a crucial component of the internet infrastructure that converts human-readable domain names like www.google.com into IP addresses that computers use to communicate with each other.

When you type https://www.google.com into your browser and hit Enter, your computer sends a DNS request to a DNS server to find the IP address associated with that domain name. This request is initiated by the client computer and is typically sent to the local DNS resolver or cache, which is a software component that stores previously resolved DNS queries to speed up the process of resolving subsequent requests.

If the local resolver does not have the requested information in its cache, it sends a recursive query to a DNS root server, which is the starting point for the entire DNS system. The root server responds with a referral to the top-level domain (TLD) server for the domain name in question, such as .com, .net, or .org.

The TLD server is responsible for managing the domain names within its top level domain. It responds to the query with a referral to the authoritative name server for the specific domain name in question, which is responsible for storing the IP address records for that domain.

The authoritative name server responds to the DNS request with the IP address of the website's server. The local resolver then caches this information and sends it back to the client computer, which can now initiate a TCP/IP connection with the website's server to request the website's content. Overall, the DNS request is a critical component of the internet infrastructure that enables us to access websites and other online resources using human-readable domain names. By understanding how DNS works, we can better appreciate the complexity of the internet and the technology that powers it.

TCP/IP

Now, we move on to the TCP/IP. TCP/IP stands for Transmission Control Protocol/Internet Protocol. This is the set of rules that governs the transfer of data over the internet. When you type https://www.google.com into your browser and press enter, your computer uses TCP/IP to establish a connection with Google's server.

So, how does this work in practice? Imagine you're sending a package through the mail. You need to put it in an envelope, address it to the recipient, and send it through the postal service. Similarly, when you type a website address into your browser, your computer puts the request into an "envelope" called a packet. The packet contains the website address you want to visit and is addressed to the website's server.

Next, your computer sends the packet through the internet using TCP/IP. This protocol breaks the packet down into smaller pieces called segments and sends them to the destination server. The segments travel through multiple networks and routers, which are like post offices, until they reach the server.

Once the server receives the packet, it sends a response back to your computer in the form of another packet. The packet contains the website's data, such as HTML files, images, and videos. Just like before, the response packet is broken down into segments and sent back to your computer using TCP/IP.Your computer then reassembles the segments into a complete packet and displays the website on your screen. This entire process happens in a matter of seconds, thanks to the speed and efficiency of TCP/IP.

In summary, TCP/IP is responsible for breaking down data into packets and sending them across the internet to their destination. It ensures that data is transmitted reliably and efficiently, making it an essential component of the internet infrastructure.

To make this more relatable, think of TCP/IP like a highway system. Just as cars need roads to travel from one location to another, data packets need TCP/IP to travel across the internet. TCP/IP ensures that the packets reach their destination quickly and reliably, just like roads ensure that cars can reach their destination without delays or accidents.

Firewall

A firewall is a security system that monitors and controls incoming and outgoing network traffic based on predetermined security rules. Think of a firewall as a barrier or a gatekeeper that stands between your computer and the internet. Its job is to protect your computer and network from unauthorized access or malicious attacks from the outside world.

When you type in https://www.google.com, the firewall will check if the request is legitimate and if it complies with the security policies in place. It will examine the request's source, destination, protocol, and content to make sure it's safe to proceed. If the request passes the security check, the firewall will allow the traffic to pass through to the web server that hosts https://www.google.com. On the other hand, if the request is deemed suspicious or violates the security rules, the firewall will block the traffic and prevent it from reaching its destination.

To help you visualize the firewall step, imagine yourself entering a high-security building. Before you can enter, you have to go through a security checkpoint. The security personnel will check your identification, scan your belongings, and ask you questions to make sure you're authorized to enter the building. If you pass the security check, you'll be allowed to proceed. However, if you fail to meet the security requirements or raise suspicion, you'll be denied entry.

Similarly, the firewall acts as a security checkpoint that verifies your request before allowing it to proceed to the web server. It acts as a barrier between your computer and the internet to protect you from potential cyber threats.

HTTPS/SSL

The next step in the process is establishing a secure connection between your computer and the website's server. This is done through the use of HTTPS, which stands for Hypertext Transfer Protocol Secure, and SSL, which stands for Secure Sockets Layer.

So, what exactly is HTTPS/SSL and how does it work?

First, let's start with HTTP, which is the protocol that allows your browser to communicate with web servers to request and receive web pages. However, HTTP is not a secure protocol and any information sent over HTTP can be intercepted and read by anyone who is monitoring the connection. This is where HTTPS comes in.

HTTPS is the secure version of HTTP and it uses encryption to protect the data that is transmitted between your computer and the web server. Encryption is the process of converting plain text into a secret code, making it unreadable to anyone who does not have the key to decode it.

To establish an HTTPS connection, the web server needs to have an SSL certificate installed. This certificate contains a public key and a private key. The public key is used to encrypt the data and the private key is used to decrypt it.

When you type https://www.google.com into your browser and press enter, your browser initiates a handshake with the web server to establish an HTTPS connection. During the handshake, your browser sends a request to the web server for its SSL certificate. The web server then sends its SSL certificate back to your browser, which checks to make sure that it is valid and issued by a trusted Certificate Authority (CA).

If everything checks out, your browser generates a session key and encrypts it using the public key from the web server's SSL certificate. The encrypted session key is then sent to the web server. The web server decrypts the session key using its private key and sends a confirmation back to your browser to let it know that the connection has been established.

Now that the HTTPS connection is established, any data that is transmitted between your computer and the web server is encrypted and secure. This includes any personal information that you enter, such as login credentials or credit card numbers.

To visualize this process, imagine that you are sending a secret message to a friend. You write the message on a piece of paper and then lock it in a box with a padlock. You send the box to your friend, who has the key to unlock the padlock and read the message. In this scenario, the message is the data that you are transmitting and the padlock is the encryption used by HTTPS/SSL to protect the data during transmission.

Load Balancer

Now your browser has established a secure connection with one of Google's servers. But what if millions of other users are also trying to access Google at the same time? This is where load balancing comes in.

A load balancer is a special type of server that helps distribute incoming network traffic across multiple servers. It acts as a traffic cop, routing requests from clients to different servers in a way that maximizes efficiency and minimizes downtime.

In the case of Google, they use load balancers to distribute traffic across multiple servers in different data centers around the world. This helps ensure that users can access Google quickly and reliably, no matter where they are located.

But how does a load balancer decide which server to send each request to? This is where algorithms come into play. Load balancers use different algorithms to distribute traffic in different ways.

For example, a simple algorithm is round-robin, which simply sends requests to each server in turn. Another algorithm is least connections, which sends requests to the server with the fewest active connections at that time.

There are also more advanced algorithms that take into account factors such as server response time, server capacity, and geographic location. These algorithms help ensure that traffic is distributed in a way that optimizes performance and minimizes downtime.

To visualize how load balancing works, imagine a busy restaurant with multiple servers taking orders from customers. A single server might get overwhelmed bythe number of orders, leading to slower service and frustrated customers. But if there were multiple servers, each with their own section of tables to serve, the workload would be spread out more evenly, leading to faster service and happier customers.

In the same way, a load balancer helps ensure that traffic is evenly distributed across multiple servers, leading to faster and more reliable access to websites like Google.

Web Server

After the load balancer has determined which server to send the request to, the web server takes over. A web server is a specialized computer that is designed to store and deliver website files to clients. When you type in a website address, the client computer sends a request to the web server for the files that make up the website.

The web server then responds to the client's request by sending the necessary files over the internet. These files typically include HTML documents, images, videos, and other types of media that make up the website.

Web servers use a variety of protocols to send and receive data, but one of the most common is the Hypertext Transfer Protocol (HTTP). However, since we typed in https://www.google.com, we are actually using the secure version of HTTP, known as HTTPS, which uses encryption to ensure that data transmitted between the client and server is secure as explained earlier in the article.

When the web server receives the HTTPS request from the client, it responds by establishing a secure connection using a protocol called SSL (Secure Sockets Layer) or its successor, TLS (Transport Layer Security). SSL/TLS uses a combination of public and private key encryption to secure the connection and ensure that the data being transmitted cannot be intercepted or tampered with by third parties.

Once the secure connection is established, the web server delivers the requested website files to the client, which then renders the website in the browser for the user to see.

To help you visualize this process, imagine that you are at a restaurant and want to order a meal. The web server is like the kitchen of the restaurant, where all the food is stored and prepared. When you place an order with the waiter (your client computer), the waiter sends the order to the kitchen (web server) for the chef to prepare. The chef (web server) then cooks the meal (website files) and sends it back to the waiter (client computer) to deliver to you. Just like how the chef ensures that the meal is cooked to your specifications, the web server ensures that the website files are delivered correctly and securely to your browser.

Application Server

After the web server processes the request from the client, it may need to interact with an application server to perform more complex tasks. In the case of Google, the application server is responsible for handling search queries and providing relevant results to the user.

When a user types a search query into Google and hits Enter, the request is sent to the web server, which then communicates with the application server to process the query. The application server retrieves the relevant data from Google's vast database and sends it back to the web server for formatting and display.

To better understand this process, let's take a look at an example. Suppose a user types "best pizza places near me" into the Google search bar. After the DNS request, TCP/IP connection, firewall, HTTPS/SSL, and load balancer steps, the web server receives the request and sends it to the application server.

The application server then uses complex algorithms to search through Google's database and retrieve the most relevant results for the user's query. In this case, the application server would search for pizza places near the user's location and rank them based on various factors such as ratings, reviews, and distance.

Once the application server has retrieved the relevant data, it sends it back to the web server, which formats it into the familiar Google search results page. The page includes information such as the name, address, and rating of the top pizza places near the user's location.

All of this happens in a matter of seconds, thanks to the powerful infrastructure and advanced technology that Google has developed over the years. The application server is just one piece of this complex puzzle, but it plays a crucial role in providing users with the fast, accurate search results that they have come to expect from Google.

Database

Great! Let's talk about the last component, the database. After the application server has processed the user's request and generated a response, it needs to retrieve the data it needs to send back to the user. In the case of Google, this data is stored in a massive database, which is responsible for storing and organizing vast amounts of information, such as search queries, indexed web pages, and user data.

When a user types in a search query, the application server generates a request for the relevant data from the database. The database then searches through its vast stores of information to find the necessary data, which it then sends back to the application server. The application server then generates the HTML and other content that make up the page and sends it back to the user's browser to be rendered.

One of the ways that Google manages its massive database is through a technology called Bigtable. Bigtable is a distributed database system that is designed to handle massive amounts of data across many servers, providing high availability and scalability. By distributing the data across multiple servers, Bigtable can provide fast access to the data and handle massive amounts of traffic.

To help visualize how the database step fits into the process of loading a website, imagine a librarian retrieving a book from a massive library. Just as a librarian needs to search through many books to find the one that the user is looking for, the application server needs to search through a massive database to find the relevant data. The database is like the library, with its many shelves of books, and the application server is like the librarian, searching for the book that the user needs.

In summary, the database step is an essential part of the process of loading a website like Google. It is responsible for retrieving the vast amounts of data that make up the content of the site, and technologies like Bigtable are critical for managing the massive amounts of data that Google handles every day. By understanding how the database step fits into the process of loading a website, we can better appreciate the complexity of the technology that powers the websites we use every day.

Conclusion

To conclude this, accessing a website like Google may seem like a simple task, but there are many complex processes happening behind the scenes to make it possible. From DNS lookups and TCP handshakes to HTTPS encryption and server processing, every step is critical to delivering a seamless and secure browsing experience. Understanding these processes can help us appreciate the incredible technology that makes our digital lives possible.

References