what happens when you type https://www.google.com in your browser and press Enter.
Have you ever wondered what happens when you type a website address in your browser and press Enter? Let's take the example of google.com to understand the various steps involved in displaying a website in your browser.
Below are the things that happen behind the scene:
DNS Request: DNS, or the Domain Name System, translates human-readable domain names (for example, www.amazon.com) to machine-readable IP addresses (for example, 192.0.2.44). When you type a website address in your browser, such as https://www.google.com, your computer doesn't immediately know the IP address associated with that domain name. Instead, it has to query a DNS (Domain Name System) server to find out the IP address.
The DNS is like a phone book for the internet. It's a distributed system that translates domain names, like www.google.com, into IP addresses, like 172.217.6.68. Every time you visit a website, your computer sends a DNS request to a DNS server to find the IP address associated with the domain name.
The DNS request typically goes to a recursive DNS server, which checks its cache to see if it already knows the IP address for the domain name. If it doesn't have the IP address cached, it sends a request to a root DNS server. The root DNS server responds with the IP address of the top-level domain (TLD) server for the domain name.
The recursive DNS server then sends a request to the TLD server, which responds with the IP address of the authoritative DNS server for the domain name. The authoritative DNS server is responsible for storing the IP address associated with the domain name.
Once the recursive DNS server receives the IP address from the authoritative DNS server, it caches the IP address and sends it back to your computer. Your computer can then use the IP address to establish a connection with the server that hosts the website.
TCP/IP: Once your computer has obtained the IP address for the website you're trying to visit, it needs to establish a TCP/IP connection with the server that hosts the website. TCP/IP (Transmission Control Protocol/Internet Protocol) is a set of rules that governs how data is transmitted over the internet.
TCP is responsible for breaking down the data into smaller packets and ensuring that each packet is delivered to the correct destination. When your computer establishes a TCP connection with a server, it sends a message called a SYN (synchronize) packet to the server. The server responds with a SYN-ACK (synchronize-acknowledge) packet to confirm the connection.
IP, on the other hand, is responsible for addressing and routing the data packets to their destination. Each packet is assigned a unique IP address that identifies the sender and recipient of the packet.
Once the TCP/IP connection is established, your computer and the server can begin to exchange data. Your computer sends an HTTP (Hypertext Transfer Protocol) request to the server, which includes the domain name of the website you're trying to visit, as well as any additional information that the server needs to generate the web page.
The server responds with an HTTP response, which includes the web page content, as well as any additional information that your browser needs to render the page properly, such as images, stylesheets, and scripts.
Throughout this process, TCP/IP ensures that the data is transmitted reliably and in the correct order. If any packets are lost or corrupted during transmission, TCP/IP will automatically retransmit them to ensure that the data is delivered correctly.
Overall, TCP/IP is a crucial component of the internet infrastructure, as it enables computers and servers to communicate with each other reliably and securely.
Firewall: A firewall is a security device that monitors and controls incoming and outgoing network traffic based on predefined security rules. When you enter a website address in your browser and press Enter, the firewall on your computer or network may inspect the outgoing request to ensure that it meets the security requirements.
Firewalls work by analyzing the packets of data that are transmitted between your computer and the server hosting the website. They can block incoming traffic that doesn't meet predefined security criteria, such as traffic from suspicious IP addresses or traffic that matches known attack patterns.
Firewalls can also block outgoing traffic that doesn't meet security requirements, such as traffic that contains sensitive data or traffic that violates company policies. In addition, firewalls can prevent unauthorized access to your computer or network by blocking incoming traffic that attempts to exploit vulnerabilities in your system.
Firewalls can be implemented at various levels of the network infrastructure, including at the host level, the network level, and the application level. Host-based firewalls run on individual computers and can provide an additional layer of security against malicious software or hackers.
Network firewalls are located at the perimeter of the network and can protect against incoming traffic that is trying to penetrate the network. Application firewalls are designed to protect specific applications, such as web servers, from attacks that exploit vulnerabilities in the application.
HTTPS/SSL: When you enter a website address in your browser and press Enter, your browser sends an HTTP request to the server hosting the website to retrieve the web page content. However, this process is not secure, as the data transmitted between your browser and the server can be intercepted and read by third parties.
To address this security issue, HTTPS (Hypertext Transfer Protocol Secure) was developed. HTTPS is a protocol that encrypts the data transmitted between your browser and the server, making it difficult for third parties to intercept and read the data.
HTTPS is secured using SSL (Secure Sockets Layer) or TLS (Transport Layer Security) certificates. These certificates are digital files that are installed on the server hosting the website, and they contain information that is used to encrypt and decrypt the data transmitted between your browser and the server.
When you enter a website address in your browser and press Enter, the server responds with its SSL/TLS certificate, which contains the public key needed to encrypt the data. Your browser then uses the public key to encrypt the data before sending it to the server.
The server then uses its private key to decrypt the data and send a response back to your browser. Your browser can then use the public key again to decrypt the response and display the web page content.
By encrypting the data transmitted between your browser and the server, HTTPS/SSL provides an additional layer of security that helps protect against eavesdropping, tampering, and other forms of cyber attacks.
Overall, HTTPS/SSL is an important component of web security, as it helps protect sensitive data transmitted between your browser and the server, such as login credentials, financial information, and personal information.
Load Balancer: A load balancer is a device or software that distributes incoming network traffic across multiple servers. When you enter a website address in your browser and press Enter, the request is sent to a load balancer, which determines the best server to handle the request based on a variety of factors, such as server load, geographic location, and server capacity.
Load balancing helps ensure that website traffic is evenly distributed across multiple servers, which can improve website performance and availability. By distributing traffic across multiple servers, load balancing can help prevent overloading a single server, which can cause website downtime or slow website performance.
Load balancing can be implemented at various levels of the network infrastructure, including at the application level, the network level, and the global level. Application-level load balancing is designed to distribute traffic across multiple servers that are hosting a specific application, such as a web server or database server.
Network-level load balancing is designed to distribute traffic across multiple servers that are located on different networks or geographic regions. Global load balancing is designed to distribute traffic across multiple data centers that are located in different geographic regions.
Web server: A web server is a software application that responds to HTTP requests from web browsers and serves web pages and other web content to users. When you enter a website address in your browser and press Enter, your browser sends an HTTP request to the web server that is hosting the website.
The web server then processes the request and sends the web page content back to your browser. Web servers can serve static web pages, which are pre-defined HTML pages that do not change, or dynamic web pages, which are generated on the fly by server-side scripting languages such as PHP or ASP.NET.
Web servers can be configured to support various web technologies and protocols, including CGI (Common Gateway Interface), FastCGI, PHP, ASP.NET, and others. Web servers can also support various security features, such as HTTPS/SSL, authentication, and access control.
Some popular web servers include Apache, Nginx, IIS (Internet Information Services), and Lighttpd. Each web server has its own set of features, performance characteristics, and security capabilities
Application server: An application server is a software platform that provides a runtime environment for web applications. When you enter a website address in your browser and press Enter, the web server that is hosting the website may send the request to an application server to generate dynamic web pages.
Application servers provide a range of services and features to support the development, deployment, and management of web applications. These services and features may include support for server-side scripting languages, database access, session management, load balancing, and caching.
Application servers can be configured to support a wide range of web technologies, including Java, PHP, .NET, and others. Each application server has its own set of features, performance characteristics, and security capabilities.
Some popular application servers include Apache Tomcat, JBoss, WebSphere, and WebLogic. Each of these application servers provides a range of services and features to support the development and deployment of web applications.
A database is a structured collection of data that can be accessed, managed, and updated by computer programs. When you enter a website address in your browser and press Enter, the web server that is hosting the website may send requests to a database to retrieve data needed to generate dynamic web pages.
Databases are a critical component of modern web applications, as they provide a reliable and efficient way to store and retrieve data. Databases can be used to store a wide range of data, including user profiles, product catalogs, order histories, and more.
There are several types of databases, including relational databases, NoSQL databases, and graph databases. Each type of database has its own set of features, performance characteristics, and security capabilities.
Relational databases are the most common type of database and are designed to store data in tables with predefined relationships between them. NoSQL databases are designed to handle unstructured data, such as social media posts and user-generated content, and are typically more scalable than relational databases. Graph databases are designed to store and manage data that is represented as a graph, such as social networks and recommendation systems.
Some popular databases include MySQL, PostgreSQL, MongoDB, and Neo4j. Each of these databases provides a range of features and capabilities to support the storage, retrieval, and management of data.
In conclusion, typing a website address and pressing Enter involves several steps that are critical to the functioning of the web infrastructure. These steps include sending a DNS request, establishing a TCP/IP connection, passing through a firewall, encrypting data using HTTPS/SSL, balancing the load across multiple servers, generating dynamic content using an application server, and retrieving data from a database. Each of these steps plays a significant role in ensuring that web pages are displayed quickly, reliably, and securely.
Web infrastructure has become an essential part of our daily lives, enabling us to access a wealth of information and services on the internet. By understanding how the web infrastructure works, we can better appreciate the technologies that power the web and continue to improve its performance, reliability, and security.
We hope this blog post has provided you with valuable insights into the process of typing a website address and pressing Enter. We encourage you to continue exploring the fascinating world of web technologies and to share your thoughts and experiences with us in the comments section below.
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