On DNS; Registrar -vs- Hosts -vs- Registry Operators

Pavol Kutaj
4 min readJan 14, 2021


  • the question is the basic terminology behind domain name services: who are central organizations taking care of the domain name registry; who are registrarsl who are hosts

… and how to get this information without leaving VSCode, ideally (i.e. with a powershell script and some free-tier of an dedicated web service)

1. registrars VS hosts vs registry operators

  • DOMAIN REGISTRAR is the subject where domain names are finally purchased
  • DNS HOST is the service/server authoritative for hosting your DNS records
  • there are hosting providers that offer domain registration
  • there are registrars that offer DNS hosting, but the two should not be confused
  • selecting a domain name is the first step you make when building a web site
  • this semantical layer of the internet, technically, computers are connected with ip addresses
  • registration means going through
  1. Purchase a domain from DNS REGISTRAR, which is a company/subject that directly deals with the REGISTRY OPERATORS FOR THE TOP LEVEL DOMAIN
  2. Registrar makes sure you own the domain by registering it to you with registry operators
  3. You/Registrar need to select a DNS host — at Registrar level you specify the Name Servers hosting your information

4. DNS host stores the ZONE FILE containing all the DNS records about your DOMAIN. If the example below would have a different registrar and host, the interface would differ there.

  • the global list of domain names is managed by IANA (International Assigned Numbers Authority)


  • IANA is a department of ICANN (Internet Corporation for Assigned Names and Numbers) a nonprofit running the root zone management in the DNS
  • whois command is querying the domain name registry
  • but the registrar is too up in the hierarchy to the common customers
  • usually, a domain name is purchased through a WEB HOSTING PROVIDER that does the work for them and register a domain through the registries on customer’s behalf
  • DNS HOST are servers hosted by DNS HOSTING PROVIDERS and these servers authoritatively respond for your domain
  • Sometimes, registrars also offer DNS hosting, but it should not be confused
  • DNS Host is mentioned by names of nameservers in the NAMESERVERS part of the whois lookup

3. whois as a protocol

  • whois is a query and response protocol for querying DBs storing registered users/assignees of internet resources (domain names, IP address blocks)
  • whois is a standard drafted by the internet society
  • whois gets you info on the registrar-level
  • nslookup gets you info on the dns-host level (zone file informatino)
  • documented in RFC 3912 — WHOIS Protocol Specification

4. example: whois in terminal

  • the following script is creating and parsing a whois request
  • note: it is relying on jsonwhois.io where you need to register to get your own $apiKey
<# TODO: BRANCH BASED ON THE POWERSHELL VERSION, use invoke-webrequest for non-posh-core #>param(
[Parameter(Mandatory = $true)][string]$domainName,
[string]$apiKey = "JKS2XytCLNfkYg7i490AnSDo4QZ74lxn"
$domainIntro = @"
___|___| mrPaul's WHOIS in Terminal
"@$domainInfo = curl "https://api.jsonwhois.io/whois/domain?key=$apiKey&domain=$domainName" | ConvertFrom-Json
Write-Host $domainIntro -ForegroundColor Cyan
Write-Host "1. THE BASICS" -ForegroundColor Cyan
$domainInfo.result | Select-Object name, created, changed, expires, dnssec, registered | Format-List
Write-Host "2. REGISTRAR" -ForegroundColor Cyan
$domainInfo.result.registrar | Format-List
Write-Host "3. NAMESERVERS`n" -ForegroundColor Cyan
$domainInfo.result.nameservers | Format-List | Write-Host "`n"

5. demo

whoiscmdlet whois.ps1 at command pipeline position 1
Supply values for the following parameters:
domainName: amazon.com
% Total % Received % Xferd Average Speed Time Time Time Current
Dload Upload Total Spent Left Speed
100 850 100 850 0 0 850 0 0:00:01 --:--:-- 0:00:01 1158
___|___| mrPaul's WHOIS in Terminal
1. THE BASICSname : amazon.com
created : 1994-11-01 05:00:00
changed : 2019-05-07 20:09:37
expires : 2024-10-31 04:00:00
dnssec : True
registered : True
2. REGISTRARid : 292
name : MarkMonitor Inc.
email :
url :

6. sources



Pavol Kutaj

Today I Learnt | Infrastructure Support Engineer at snowplow.io with a passion for cloud infrastructure/terraform/python/docs. More at https://pavol.kutaj.com