A domain name is the unique address of a website. Any user can access a website through that specific address.
Firstly each computer on the internet has an internet protocol address. This address consists of numbers, so it is not easy to remember. The human cannot recognize the internet protocol (IP) address. When a user enters the website address (alphabets) in the address bar or URL section, a primary conversion of the URL takes place. It converts the alphabets of URL to the internet protocol address. Secondly the web browser checks for internet cache. If not found, it requests the corresponding DNS.
Domain name system (DNS):
Domain name system saves the IP address of a computer as desired alphabets (domain name). Certainly it works like a phonebook directory of a mobile phone. Different IP addresses of different computers on the internet are saved with domain names when a user enters the URL and tries to access the website DNS looks in its directory for the internet protocol address of the specific website.
Domain categories:
Second level domain:
The second level domain corresponds to the company, organization, or business. Moreover in a domain, it is the left part of the dot. For example, in google.com, google is the second-level domain name.
Top-level domain:
A top-level domain is the extension of a website domain. In a domain name, it is at right to dot. For example, in the above example.com is the top-level domain.
Top-level domains consist of different extensions. Each extension defines the category of the second-level domain. (.com, .org, gov, .edu are most common top-level domains)
When a user enters “google.com” in the URL section of the web browser, the browser looks for an internet cache or requests a Recursive DNS server to look for the IP address associated with google.com. Recursive DNS is found at the internet service provider or public DNS server. This process is beautifully illustrated in the below image.
Root Server:
If the recursive DNS does not find the associated website’s IP address, a request to the root DNS server is made. It then asks the resolver to find in the top-level domain. Above all the top-level DNS responds to provide the relevant domain’s IP address. The DNS server gives to IP address to the browser. The web browser sends HTTP (hyper-text transfer protocol) requests to access hypertext files.
Authoritative name server:
An authoritative name server is only responsible to respond to specific regions. In short it records the latest information from hosts.
Moreover communication between different computers on the internet takes place by using different protocols.
Different types of protocols.
There are different rules to govern the network, communicate and transfer data. These rules are called protocols. There different types of protocols,
Transmission Control Protocol (TCP):
Transmission control protocol works with internet protocol. In other words the transmission control protocol is responsible for the transfer of files.
Internet protocol (IP):
Internet protocol is responsible for the transfer of data packets to the exact computer (destination). To clarify it is the first tool that helps to interconnect the computers at different locations.
Simple Mail Transfer Protocol (SMPT):
Simple mail transfer protocol is responsible for transferring emails from one computer to the destination (computer). Furthermore it gets the address (mail address) and transfers the email to the destination.
Post Office Protocol (POP3):
Post office protocol is responsible for receiving incoming emails from different senders.
File Transfer Protocol (FTP):
File transfer protocol is responsible for the transfer of files (e.g., media) among different computers.
Hypertext transfer protocol (HTTP):
It is responsible for transferring hypertext files (web pages). When a computer connects to a website, it accesses its hypertext files first.