What Is a Domain Name and How DNS Works A Guide for Node.js Developers

What Is a Domain Name?

A domain name is a human-readable address for a website (e.g., yourdomain.com). It maps to an IP address (e.g., 12.34.56.78) that computers use to find each other on the internet.

Why Use a Domain Name?

1. Memorable Users remember yourdomain.com not 12.34.56.78
2. Professional A custom domain looks professional for production apps
3. Required for SSL Let's Encrypt needs a domain name to issue certificates
4. Stable IP addresses change; domain names stay the same
5. Email Enable custom email addresses (e.g., [email protected])

Domain Name Structure

   subdomain.domain.TLD
   api.yourdomain.com

• TLD (Top-Level Domain) .com, .org, .net, .dev, .io
• Domain yourdomain (the name you registered)
• Subdomain api, www, admin (optional prefix)
• Root domain yourdomain.com (no subdomain)

How DNS Works

DNS (Domain Name System) is like a phone book for the internet. It translates domain names to IP addresses.

When a user visits api.yourdomain.com:

1. Browser checks cache Is the IP already known?
2. Recursive DNS server The user's ISP DNS server checks its cache
3. Root nameserver Directs to the TLD nameserver (.com)
4. TLD nameserver Directs to the domain's nameserver
5. Domain nameserver Returns the A record (IP address)
6. Browser connects To the IP address returned

This process takes milliseconds and is cached at each level for future requests.

DNS Record Types

Key Records for Node.js Deployment

A Record Points your domain to your EC2 IP:

Type: A
Name: api (or @ for root)
Value: 12.34.56.78 (your EC2 Elastic IP)
TTL: 300 (5 minutes)

CNAME Record Points a subdomain to another domain:

Type: CNAME
Name: www
Value: yourdomain.com
TTL: 300

TTL (Time to Live)

TTL is how long DNS servers cache the record before checking again:

• 300 seconds (5 min) Good for testing (changes propagate quickly)
• 3600 seconds (1 hour) Good for production (balance of speed and flexibility)
• 86400 seconds (24 hours) Maximum caching (for stable records)

When making DNS changes, use a short TTL first, then increase it after the change is confirmed.

Where to Buy Domains

Popular domain registrars:

• Namecheap Affordable, free WHOIS privacy
• GoDaddy Popular but upsells heavily
• Google Domains Now transferred to Squarespace
• Cloudflare At-cost pricing, free DNS
• AWS Route 53 Good for AWS-heavy projects

DNS Providers

You can use a different DNS provider than your registrar:

• Cloudflare Free, fast, with CDN and DDoS protection
• AWS Route 53 Good for AWS integrations
• Google Cloud DNS Good for GCP integrations

The Takeaway

A domain name is a human-readable address that maps to an IP address via DNS. For Node.js deployment, create an A record pointing your domain (or subdomain) to your EC2 Elastic IP. DNS propagation takes minutes to hours depending on TTL. Use Cloudflare for free DNS with CDN and DDoS protection, or AWS Route 53 for AWS integration.