Domain
About 5 min read
Last updated: 2026-04-14
What Is a Domain
A domain is the human-readable name of a website, such as example.com or google.co.jp. It serves as an easy-to-remember label for a server's location. During actual communication, DNS translates the domain name into an IP address.
Domain Structure
.com, .jp, .org, etc. Indicates purpose or country.example part. The unique name of the site.www or mail, etc. Used to separate services within the same domain.Domains and Phishing Prevention
Phishing scams use domain names that closely resemble legitimate ones. A common trick is placing the real name in a subdomain, such as amazon.co.jp.evil.com. Remember that the real domain is the part just before the last dot.
Domain Registration and Management
Domains are obtained through registrars (such as GoDaddy, Google Domains, or Namecheap). They require annual fees, and if renewal is missed, the domain expires and may be acquired by someone else.
To learn more about this topic, see also How to Read URLs Safely.
Common Misconceptions
- A .co.jp domain means it's a safe Japanese company
- .co.jp domains are available to Japanese corporations, but being a corporation does not guarantee safety.
- Once you buy a domain, you own it forever
- Domains require annual renewal fees. If you forget to renew, the domain expires.
Domain vs. IP Address
Domain
A human-readable name. Translated to an IP address by DNS.
IP Address
A numerical address used by computers. Used for actual communication.