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

Introduction

You open up your browser, type in your favorite website and hit enter. Instantly, you're greeted with the familiar webpage - assuming you have stable internet connection. But have you ever stopped to wonder what happens behind the scenes during this seemingly simple act?

Under the hood, a complex network of systems works together to connect you to your favorite website. From your device's browser and operating system to distant servers and the underlying technologies that power them, each component has a crucial role in getting you to your desired destination.

In this blog post, we'll embark on a behind-the-scenes adventure to explore the networking concepts that power the internet. To illustrate these concepts, we'll use a familiar example: visiting "https://www.google.com" for the first time. Ready to dive into the fascinating world of web browsing? Let's begin!

Understanding the URL

First, let's clarify what a URL is. A URL, or Uniform Resource Locator, is a string that points to the location of a resource on the internet. It acts like a roadmap that tells your browser exactly where to find the information you're looking for.

In our example, https://www.google.com is our URL:

• "https": This is the protocol, indicating a secured connection.

• "www": A subdomain, traditionally representing the World Wide Web. it is a way to organize different sections of a website. it is a common subdomain but not always necessary.

• "google.com": The domain name, which points to the IP address of Google's server.

An IP address is the series of numbers that specifies the location of an internet device. It's like a unique identifier that allows devices to communicate with each other. Just as you need a physical address to receive mail, a device needs an IP address to receive data over the internet. While the domain name is a human-readable address, the IP address is a numerical address that computers use to identify each other on the network.

Now we have the domain name, we need to find the IP address of the Google server to connect to it. But how do we do that?

In the next section, we'll explore the process of resolving the domain name to an IP address.

The DNS Request: Finding the Server's Address

To connect to the server, we'd need the IP address associated with google.com. To get this, the browser first searches its internal caches to see if it has a recent copy of it. If it is available in the browser's cache, it can use it immediately without needing to perform a DNS lookup, saving time and network resources. If the IP address is unavailable, then the browser queries the default DNS server, usually provided by your Internet Service Provider (ISP), or a third-party DNS service like Cloudflare.

A DNS, or Domain Name System, is a database that maps domain names to IP address, like an address book. So, when you type in a URL, your browser can find the right server to connect to. The DNS database is distributed across many servers worldwide, with each server responsible for a portion of the domain namespace. This allows for efficient lookups and high availability of the DNS system

The DNS process involves several steps, which are well-illustrated by this comic. In a nutshell, the browser sends a request to the DNS server, which then checks its own cache and contacts other DNS servers to find the IP address associated with google.com. Eventually, the DNS server responds with the IP address, let's say 4.1.4.2.

Now that we have the IP address, we need to connect to the server at that address. But how do we connect to the server at 4.1.4.2? How are our requests transported to their destination and how are our responses delivered back? This is where Internet Protocols comes in.

In the next section, we'll explore the concept of Internet Protocols and how it enables communication with devices on the internet. Let's take a look.

TCP/IP: The Protocols That Power the Internet

The internet relies on an intricate system to enable communication between devices. The TCP/IP model describes this system as four distinct layers that break information into smaller chunks for transport through mediums like Wi-Fi, optical cables, or other data transfer methods. This layered approach ensures efficient and accurate data transmission across devices and networks.

• Network Access Layer (layer 1): This layer handles the physical connection between devices, managing the hardware and transmission media that enable data transfer.

• The Internet Layer (layer 2): This manages data routing, forwarding, and addressing to ensure that data packets reach their destination. It acts like a postal service, directing packets to the correct address on the internet.

• The Transport Layer (layer 3): This layer provides reliable data transfer services, including error recovery and flow control. It ensures that data is delivered accurately and in the correct order, much like a delivery service that guarantees your packages arrive safely.

• The Application Layer (layer 4): This enables user applications to interact with the network, allowing programs like web browsers and email clients to communicate over the internet.

Each TCP/IP model layer relies on protocols to define how data is sent and received, ensuring proper structure and management as it travels through the internet. For example, application layer protocols like HTTP (Hypertext Transfer Protocol) and FTP (File Transfer Protocol) define how data is formatted and transmitted over the internet.

Two vital protocols operate at the transport and internet layers, Transmission Control Protocol (TCP) and Internet Protocol (IP). TCP guarantees data integrity and order, while IP handles addressing and routing. These protocols are what ensure our requests and responses are directed to the right device despite the millions of devices connected to the internet.

Following our example, with the IP address of the Google server, 4.1.4.2. The Transport Layer (using TCP) ensures that our requests are delivered in the correct order and that any errors are corrected. The Internet Layer (using IP) routes our requests to the correct server and ensures that it reaches the intended recipient. The same process occurs to ensure our responses are delivered to us. This seamless interaction between TCP and IP enables fast, reliable, and efficient communication that we enjoy over the internet today.

Fun fact: The TCP/IP model is named after these two foundational protocols, TCP and IP.

Whoa, that was quite the process, but now we can communicate with the google server. So, what do we say? How do we "GET" and display the resources on the server?

In the next section let's take a look at the secret code that gets the server to respond with our request as well as how browsers display it. Let's go!!!

Wrapping things up: Getting and displaying the result

Now that we have a connection, it's time to tell Google's server what we want! We send in a special request called a HTTP GET request to the server, kind of like asking politely for a resource, Google's homepage in this case. HTTP is an application layer protocol that enables communication between web devices and the GET request is a method used to request resources from servers.

The server then responds with two things: a status code, indicating success or an error, and the actual content of the webpage, written in a language called HTML (Hypertext Markup Language). HTML acts as a blueprint, outlining the structure and content of the page.

The browser parses the HTML and sends additional GET requests to fetch other resources that may be needed. It digs through the HTML content, understanding the different elements like text, images, and buttons. It then constructs a tree-like representation called the DOM (Document Object Model) Tree, which organizes the different parts of the page. Then, using this tree structure, it renders or displays the homepage of www.google.com.

And there you have it—a quick run-through of "What happens when you type "https://www.google.com" in your browser and press Enter". Now you know how this seemingly simple task is actually powered by a host of different technologies and protocols. This complex process is a testament to the power of internet communication and the many technologies that enable it.

For those seeking a deeper dive, here's a more detailed explanation and a video.

The Server Side: The Other Half of the Story

Hold on, the server side you say? Yes, that's right

For those who dare to explore further, let's shift perspectives and look at the server side. The internet vastly relies on a server-client communication model, with clients making requests—like we just did—and servers delivering responses. Focusing solely on the client side wouldn't paint the complete picture. On that note, continuing with our earlier example of connecting to Google's server, let's dive in head-first into the server side of things. You ready?

The Firewall: Guardian of the Server

Security has always been a key concern for any internet-connected device, but more so when it concerns servers. Unlike individual users, servers face a constant barrage of potential threats, from malicious attacks to unauthorized access attempts. In fact, a single security breach can have devastating consequences for a server, making security a top priority.

To address these concerns, most servers are usually protected by a device and/or software called a firewall. A server's firewall is a security system that monitors and controls incoming and outgoing network traffic based on predetermined security rules. Firewalls are a critical component of a server's security strategy, ensuring that only legitimate traffic is allowed while keeping threats at bay. For example, a firewall might block traffic from a known malicious IP address or restrict access to certain ports or services.

Following our example from earlier, upon connecting to Google's server, the firewall inspects our traffic to ensure our request is safe and valid before granting access. By controlling traffic and enforcing strict security rules, firewalls play a crucial role in maintaining the availability of server resources, preventing security breaches and protecting sensitive data.

Secure Connections: The Power of HTTPS and SSL

While firewalls may protect servers from various threats, client-server communications weren't very secure prior to HTTPS. Sensitive information could be intercepted and compromised as HTTP, transmitted data in plain text. This vulnerability led to common attacks known as "man-in-the-middle" attacks.

With the introduction of HTTPS (Hypertext Transfer Protocol Secure), client-server communications are now secured with SSL (Secure Socket Layer) and TLS (Transport Layer Security) encryption. This protocol offers robust protection for sensitive information, such as passwords and credit card numbers, by encrypting all transmitted data. By using cryptographic keys, HTTPS provides benefits such as:

• Encryption: Scrambles data so only intended parties can read it.

• Authentication: Confirms the server's identity through certificates.

• Data Integrity: Detects any alterations to the data during transit.

These features make HTTPS and SSL/TLS essential for safe online interactions, by providing a secure and trusted client-server connection, and protecting sensitive information from interception and theft.

You might've noticed we used HTTPS protocol while connecting to google.com, making all our communications with the server secured, encrypted and safe from compromise and eavesdropping.

Load Balancers: The Traffic Cops of the Internet

Whoa, that was quite the discussion on security! It really highlights its importance. Now, let's shift gears and explore how servers handle massive traffic while remaining available most of the time. To achieve this, most server systems are designed to be redundant, with multiple instances of a particular resource to ensure availability even if one fails. These servers are typically grouped in data centers, forming server clusters or farms.

But then, how do all this come together? Does this mean we connect to a different server each time? If so, how is this managed and how are all these IP addresses managed?

Whoa there, calm your horses! That's quite a lot of questions. Let's tackle them one at a time. This is where the concept of load balancing comes into play. Technically, we connect to the same server each time—Google's server at IP address 4.1.4.2 in our case—but the server that actually responds to our request might be different.

So, how does this work? When we connect to google.com, we first connect to a load balancer, which maps our requests to a specific server within the cluster. This server is responsible for responding to our requests, while the load balancer serves as the gateway, managing interactions without you directly accessing individual servers.

So, what exactly is a load balancer? A load balancer is a server that distributes traffic optimally across various servers in the cluster. This helps reduce the load on individual servers, extending their lifespan and overall availability. By spreading the workload, load balancers ensure that no single server is overwhelmed, resulting in faster response times and improved system reliability. This efficient management of requests ensures that users experience minimal downtime and optimal performance.

Web Servers: Gateway to the Internet

Now that we understand how traffic is managed and distributed, let's get into where the magic actually happens: web servers. You might be wondering where the HTTP GET request we sent earlier actually goes. Well, here's your answer: the web server. The web server is the application running on the server that ultimately receives our requests, processes them, and generates the responses we get back.

Web servers are constantly listening for requests on specified ports, typically based on specific protocols, such as port 80 for HTTP and port 443 for HTTPS. While web servers primarily serve static web pages, they can also be configured to deliver dynamic content. Some of the most popular web servers in use today are Nginx and Apache.

Let's go back to our example. The HTTP GET request we sent to Google's server actually gets processed by a web server behind the scenes. This server evaluates the request, prepares a response with the necessary resources, and deliver it back to your browser. Web servers are the workhorses of the internet, handling the heavy lifting of serving content to millions of users simultaneously. Essentially, browsing the web is an interaction between your browser and web servers.

Application Servers: The Key to Dynamic Content

While web servers excel at delivering static content, they fall short when it comes to dynamic interactions. This is where application servers shine. These powerful software platforms handle complex tasks like user authentication, database interactions, and personalized content generation.

For instance, when you log in to a social media platform, the application server verifies your credentials, retrieves your profile information, and dynamically generates your personalized news feed. This intricate process involves processing data, executing business logic, and ultimately delivering a tailored experience.

Popular application server technologies like Node.js, provide the foundation for building robust and scalable web applications. By acting as the intermediary between web servers and databases, application servers enable developers to create engaging and interactive online experiences.

In essence, application servers power the dynamic aspects of modern web applications, ensuring that user interactions are processed efficiently and securely. By handling complex tasks like data processing, authentication, and authorization, application servers enable websites to provide personalized experiences, process transactions, and more.

Databases: The Memory of the Web

We touched on this earlier when we discussed application servers. When you log in to a social media platform, have you ever wondered how it remembers all your information—your friends, messages, and more? The answer lies in databases.

Databases are essential for storing, organizing, and retrieving data efficiently. They are the backbone of modern web applications, enabling dynamic content and personalized user experiences, while ensuring reliability and scalability.

Databases are the foundation for countless applications and systems. They power everything from e-commerce platforms to social media networks, financial systems, and scientific research. They enable efficient data storage, retrieval, analysis, and management, supporting decision-making and innovation.

Think of a social media platform: every post, like, comment, and user profile is meticulously stored in a database. This allows platforms to personalize your experience, deliver targeted ads, and analyze user behavior.

In essence, databases are the memory of the web, storing and retrieving vast amounts of data to fuel the digital economy.

Putting it all Together

Congratulations on making it this far! You’ve got a wonderfully curious mind.

Now, let's review the incredible journey we've been on. When we type "https://www.google.com" and press Enter, we embark on a fascinating adventure through a complex network of technologies, like the DNS and protocols, like TCP/IP. This journey ultimately connects us with a server, often located miles away, which quickly "serves" up the content we request.

These specialized computers, known as servers, are designed to be redundant, secure, and highly available. They're equipped with various components that expand their capabilities and functionalities, including:

• Web Servers: Handle your requests directly, delivering the content you seek.

• Application Servers: Enable dynamic, personalized interactions.

• Databases: Store and retrieve information efficiently.

With this knowledge in our toolbox, we can now appreciate the fascinating complexity behind seemingly simple acts and glimpse the technology powering our world today. So, the next time you browse the web, remember the intricate collaboration between technologies, protocols, and infrastructure that delivers information at lightning speed.

Until next time, keep exploring and stay curious!