What is DNS ?
The Domain Name System (DNS) is a spinal cord of the internet communication that use to translates a domain name to IP addresses.Hence, request can route to right web-server server over the internet and browsers can load web-page.
The device that connected to the Internet (Computer, Laptop, Mobile Phone, IOT Devices etc.) has a unique IP address which other computer devices use them to communicate the other network device over the internet. DNS servers eliminate the need for people’s to memorize IP addresses such as 126.96.36.199 (in IPv4), or more complex newer alphanumeric IPv6 addresses such as 2001:cd00:2018:1::c629: 7334 (in IPv6).
➡ For Example – www.techmusa.com to 188.8.131.52.
➡ Domain name is – www.techmusa.com and IP – 184.108.40.206
DNS server is a very complex system of internet that maintains the IP addresses of each respective domain over the internet, on top of that it’s keep serves billion of DNS request for IP address every day.
DNS is a globally distributed database designed to translates domain names to IP addresses. DNS is classified by function into authoritative DNS and recursive DNS.
A DNS server is a computer server that contains and manage database of IP addresses and their associated domain-name or hostname’s. DNS server serve the IP address to the users against a domain-name query that trigger by a user’s system or browser.
In layman language, a computer doesn’t understand the name it only communicates with numbers and only identify the numbers only.
Since humankind having difficultly to memorize the numbers… millions of millions of numbers (IP address), so dns services was developed as a sort of “phone book” that translates the domain you enter in your browser into a computer readable IP. In sort DNS servers keep records of each domain against IP address in the DNS database.
When you open a web browser and go to any website, you don’t need to remember actual site IP address which is a long number. Instead, you enter a domain name like https://www.techmusa.com and still end up in the right place by help of DNS server.
Types of DNS Services
Authoritative name-server use to keep actual DNS record information known as DNS hosting provider or domain registrar like BigRock , HostGator and GoDaddy those DNS registration and hosting).
Basically, authoritative DNS name-servers are accountable for answering to recursive DNS nameservers with the IP “mapping” of the intended website domain-name.
Authoritative name servers contain DNS records information such as corresponding IP addresses and other necessary DNS records.
An authoritative DNS service is answering DNS queries when a user request for a website. An authoritative name server provides actual answer to your DNS queries and translating domain name into IP address so computers can communicate with each other over the internet.
Recursive DNS also known as local DNS or cache DNS recapitulates the response from the authoritative server, returns the final IP address to client’s system and caches the request result locally.
The purpose of Recursive DNS is help reduce authoritative lookups; it will attempt to find DNS query record in its local cache, if the record found in Recursive DNS cache then it answers the DNS query by providing the source or IP information. If not, it passes the query to one or more authoritative DNS servers to find the information.
The recursive DNS server always store the IP address in local server cache memory for a certain amount of time, the amount of time that the IP address is stored in cache memory is defined by the owner of the domain using a setting called “Time To Live” (TTL).