What is DNS?

DNS, which stands for Domain Name System, is essentially a dictionary that maps URLs of Internet resources to their corresponding IP addresses. Most people call it "the phonebook of the Internet".

In most cases, the IP of the first outbound DNS server is provided by the ISP, which can be configured on a per-router or per-machine basis. It's also possible to use any other DNS server by setting the corresponding IP address in the system's settings.

Any individual DNS server may route a query to a different DNS server if it doesn't have the requested DNS record.

Browsers and operating systems have their own local DNS cache which helps avoid querying DNS servers every time.

A DNS request is a query sent by a client (browser) to a DNS server. The client queries information (for example the IP address corresponding to www.google.com) in a single request. This request is followed by a single reply from the DNS server containing the IP address in question.

TCP/IP connection

TCP/IP (Transmission Control Protocol/Internet Protocol) is a suite of communication protocols that define the standards for transmitting data over computer networks, including the Internet. The TCP/IP protocol is the foundation of the internet and enables devices to communicate with each other using a common language.

At this point, the browser has received the IP address corresponding to the domain name the user typed in the browser URL tab. Using the public Internet routing infrastructure, packets from a client browser request get routed through the router, the ISP, through an Internet exchange to switch ISPs or networks, all using transmission control protocol to find the server with the IP address sent back to us from the DNS.

Once the browser finds the intended server on the Internet, it establishes a TCP connection with the server.

Firewall

A firewall is a security system that monitors and controls the incoming and outgoing network traffic based on predetermined security rules. Its primary purpose is to protect a network from external threats, such as hackers and malware.

When you type a URL like "www.google.com" into your browser, the request that your browser makes to Google's server passes through the firewall on its way. The firewall checks the incoming request to make sure it is allowed based on its security rules.

If the incoming request meets the security rules set by the firewall in front of Google's server, it is allowed through, and the browser can access the website.

However, if the request does not meet the security rules, it is blocked, and the browser is unable to access the website.

HTTPS/SSL

SSL certificates are what enable websites to move from HTTP to HTTPS, which is more secure. HTTPS is a secure version of HTTP and the S at the end stands for Secure. SSL stands for Secure Sockets Layer. They make encryption for the traffic to be possible making the data unreadable to intruders. The data is then decrypted at its destination so the end user can understand the content. In our case, using this protocol the web browser (client) and the server that is keeping the data share this data securely.

Load-balancer

A load balancer intelligently distributes traffic from clients across multiple servers without the clients having to understand how many servers are in use or how they are configured. Because the load balancer sits between the clients and the servers it can enhance the user experience by providing additional security, performance, and resilience and simplifying scaling your website.

Load balancers perform many functions in addition to just splitting traffic across servers, among them are: HTTP reverse proxy, Traffic and routing optimization algorithms, Image caching (reducing web server load), Content caching

Your request to view www.google.com will be equally balanced with all other available requests from other clients. The load balancer will allocate a server for you.

Web server

A web server can be software running on the hardware or the hardware itself that uses HTTP (Hypertext Transfer Protocol) and other protocols to respond to client requests made over the World Wide Web. The main job of a web server is to display website content through storing, processing and delivering webpages to users.

Application server

An application server is a program that resides on the server, and it’s a server programmer providing business logic behind any application. This server can be a part of the network or the distributed network.

Database

A database is an organized collection of structured information, or data, typically stored electronically in a computer system. A database is usually controlled by a database management system (DBMS). Together, the data and the DBMS, along with the applications that are associated with them, are referred to as a database system, often shortened to just a database.

I hope this gives an insight into understanding the different structures of web browsers.

thanks for the read...