DNS (Domain Name System) provides a simple way for us to communicate with devices on the internet without remembering complex numbers. Every computer on the internet has its own unique address to communicate with it called an IP address. An IP address looks like the following 104.26.10.229, 4 sets of digits ranging from 0 - 255 separated by a period. When you want to visit a website, it's not exactly convenient to remember this complicated set of numbers, and that's where DNS can help. So instead of remembering 104.26.10.229, you can remember tryhackme.com instead.
TLD (Top-Level Domain)
The rightmost part of a domain name (e.g., .com in tryhackme.com). TLDs include gTLDs (generic like .org, .biz) and ccTLDs (country codes like .uk, .ca). They help indicate the domain's purpose or origin.
Second-Level Domain
The name directly to the left of the TLD (e.g., tryhackme in tryhackme.com). It identifies the organization or entity and is what you register as your domain. Limited to 63 characters using only a–z, 0–9, and hyphens (with restrictions).
Subdomain
A prefix added before the Second-Level Domain (e.g., admin in admin.tryhackme.com). Used to organize or separate sections of a site or services. Follows the same character rules and can be chained (e.g., jupiter.servers.tryhackme.com).
A Record
Maps a domain to an IPv4 address (e.g., 104.26.10.229).
Used for directing traffic to a web server.
AAAA Record
Maps a domain to an IPv6 address (e.g., 2606:4700:20::681a:be5).
Used similarly to A records but for IPv6-enabled systems.
CNAME Record
Maps a domain to another domain (not an IP). E.g., store.tryhackme.com → shops.shopify.com.
MX Record
Specifies mail servers for the domain with priority levels. Ensures reliable email delivery by supporting fallback servers.
TXT Record
Stores arbitrary text data. Commonly used for domain verification and email sender policies (e.g., SPF).
.com)