DNS Full Form: The full form of DNS is referred to as the Domain Name System. It is a set up of a web, which allows the user to contact the correct server by entering the correct uniform resources locator into the web browser. It converts internet domain and hostnames to IP addresses and vice versa.
For example in WWW.cnn.com, ‘www’ is the hostname, ‘cnn.com’ is the domain name and ‘220.127.116.11’ is the IP address of CNN.
DNS Full Form
It is a human-readable name—like yahoo.com—that a user types in a web browser URL field. The domain names are managed by The Internet Corporation for Assigned Names and Numbers (ICANN).
Top-Level Domain (TLD)
It is the last part of a domain name. For example, the .com in yahoo.com is the Top Level Domain. Some of the most common TLDs include .com, .net, org, and .info. Country code TLDs represents particular geographical locations. For example: ‘in’ represents India, ‘eu’ – European Union, ‘gov’ – U.S. government agencies.
Second Level Domain
It is the part of a domain name which comes just before the LTD.
A subdomain is created to identify specific content areas of a web site. For example, the ‘erp’ in erp.sap.com
It is like a phone book which contains the names of domain and their associated IP addresses.
How DNS Works
When a user enters a domain name into the browser, the computer’s DNS client checks for information in a local cache. If the name is not found, then the request is sent to the DNS server. The DNS server then forwards the request to a DNS root name server. The name server looks in the domain record for the domain name, gets the corresponding IP address for a web server and returns the IP address to the DNS server. It then returns the IP address to the web browser. The web browser sends a request for the searched domain name to the IP address that it received from the DNS server. The web server at the IP address returns the web page for the domain name to the web browser, and the web browser displays the page.
- DNS is a centralized system that helps to find the website using an internet browser like chrome, safari, firefox, etc.
- There is no need to remember large numbered addresses as the domain name provides links when the name is given.
- DNS is used as a form of an additional layer of security.
- It enables the requests to be answered to the next closest node in the case of maintenance or downtime, it is smarter & it offers automatic corrections of typed words.
- When the DNS server cannot find the correct IP address, the website will not load, As the computers communicate via IP addresses & not host-names.
- ICANN can control the DNS root registry making DNS a centralized system
- Malware hijacks some DNS servers to redirect popular websites to ones that are full of advertisements or fake virus websites. To prevent this antivirus program should be installed.
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