Think of the DNS process as a relay race. Your computer starts with the domain name and passes it along to the resolver. The resolver then passes the request to the root server, the TLD server, and finally, the authoritative server, each one getting closer to the destination. Once the IP address is found, it's relayed back down the chain to your computer, allowing you to access the website.
The hosts file is located in C:\\Windows\\System32\\drivers\\etc\\hosts on Windows and in /etc/hosts on Linux and MacOS.
| DNS Concept | Description | Example |
|---|---|---|
Domain Name |
A human-readable label for a website or other internet resource. | www.example.com |
IP Address |
A unique numerical identifier assigned to each device connected to the internet. | 192.0.2.1 |
DNS Resolver |
A server that translates domain names into IP addresses. | Your ISP's DNS server or public resolvers like Google DNS (8.8.8.8) |
Root Name Server |
The top-level servers in the DNS hierarchy. | There are 13 root servers worldwide, named A-M: a.root-servers.net |
TLD Name Server |
Servers responsible for specific top-level domains (e.g., .com, .org). | Verisign for .com, PIR for .org |
Authoritative Name Server |
The server that holds the actual IP address for a domain. | Often managed by hosting providers or domain registrars. |
DNS Record Types |
Different types of information stored in DNS. | A, AAAA, CNAME, MX, NS, TXT, etc. |
| Record Type | Full Name | Description | Zone File Example |
|---|---|---|---|
A |
Address Record | Maps a hostname to its IPv4 address. | www.example.com. IN A 192.0.2.1 |
AAAA |
IPv6 Address Record | Maps a hostname to its IPv6 address. | www.example.com. IN AAAA 2001:db8:85a3::8a2e:370:7334 |
CNAME |
Canonical Name Record | Creates an alias for a hostname, pointing it to another hostname. | blog.example.com. IN CNAME webserver.example.net. |
MX |
Mail Exchange Record | Specifies the mail server(s) responsible for handling email for the domain. | example.com. IN MX 10 mail.example.com. |
NS |
Name Server Record | Delegates a DNS zone to a specific authoritative name server. | example.com. IN NS ns1.example.com. |
TXT |
Text Record | Stores arbitrary text information, often used for domain verification or security policies. | example.com. IN TXT "v=spf1 mx -all" (SPF record) |
SOA |
Start of Authority Record | Specifies administrative information about a DNS zone, including the primary name server, responsible person's email, and other parameters. | example.com. IN SOA ns1.example.com. admin.example.com. 2024060301 10800 3600 604800 86400 |
SRV |
Service Record | Defines the hostname and port number for specific services. | _sip._udp.example.com. IN SRV 10 5 5060 sipserver.example.com. |
PTR |
Pointer Record | Used for reverse DNS lookups, mapping an IP address to a hostname. | 1.2.0.192.in-addr.arpa. IN PTR www.example.com. |