DNS and DNS Types

DNS

Domain Name Server

The purpose of DNS is to translate all the inquiries into IP address, which computers can understand. it also provides a list of mail which accept Emails for each domain name.

how DNS works 

Diagram

DNS queries also known as a DNS request is a demand for information sent from a user's computer client to a server.

The Recursive is, when DNS client directly gets the IP address of a domain, by asking the name server system to perform the complete translation.

The iterative is a request for a website name or uniform resource locator (URL) that the domain name system (DNS) server reponds to with the IP address from its zone file cache, 

The Non recursive is, when a DNS client contacts the name servers, one by one, until it finds the server, containing the needed information.

Describe 

DNS server

A DNS server are internet equivalent of a phone book. they maintain a directory of domain names and translate them to internet protocol (IP) address.

DNS Resolver 

A DNS resolver (recursive resolver), is designed to receive DNS queries, which include a human readable hostname such as "www.example.com", and is responsible for tracking the IP address for that hostname. 

DNS Root Server 

A root server is part of the supporting infrastructure of the internet, and facilitates internet use by acting as the backbone of online access. is responsible for fundamental functions when it comes to translating domain names into IP address it answers client request in the domain name system's root zone.

Authoritative Name Server

An authoritative name server provides actual answer to user DNS queries such as mail server IP address or web site IP address ( A resource record). therefore it only returns answers to queries about domain names that are installed in its configuration system.

Describe 3 types of common DNS records

1. A (Host address) is the most basic and the most commonly used DNS record type. it is used to translate human friendly domain names such as "www.google.com" into IP-addresses such as 23.211.43.53. A record are the DNS server equivalent of the host file. 
2. AAAA (IPv6 host address) is used to specify the IPv6 address for a host (equivalent of the A-record type for IPv4).
3. ALIAS ( Auto resolved alias) is a virtual record type we created to provide CNAME like behavior on apex domains. 

Reference 

What Is A Domain Name Server DNS And How Does It Work | Network Solutions. (2019). Networksolutions.com. Retrieved 21 October 2019, from https://www.networksolutions.com/support/what-is-a-domain-name-server-dns-and-how-does-it-work/

DNS, M. (2019). What Is Authoritative Name Server?. Dnsknowledge.com. Retrieved 21 October 2019, from https://www.dnsknowledge.com/whatis/authoritative-name-server/

What is a Root Server? - Definition from Techopedia. (2019). Techopedia.com. Retrieved 21 October 2019, from https://www.techopedia.com/definition/23702/root-server-domain-name-system-dns

background, W. (2019). What is a root server? Definition and background. IONOS Digitalguide. Retrieved 21 October 2019, from https://www.ionos.com/digitalguide/server/know-how/what-is-a-root-server-definition-and-background/

CNAME Record - How it Works, Alternatives & Advanced Use Cases. (2018). NS1. Retrieved 21 October 2019, from https://ns1.com/resources/cname

ALIAS-Records (Auto Resolved Alias) . (2019). Simpledns.com. Retrieved 21 October 2019, from https://simpledns.com/help/alias-records