There are a lot of domain levels but three are most known, used and important.
Most used and recognized TLDs (top-level domains) are:
- ccTLD (country-code top-level domains) – established for countries, islands or territories. Consist of 2 letters;
- gTLD (generic top-level domains) – related to activity type (.com for companies, .biz for business). Consist of 3 or more letters;
- sTLD (sponsored top-level domain) – domains proposed and sponsored by private entities (such as .aero, .asia, .dev, etc).
If you are about to register a top level domain, it will look like mydomain.com. Be advised that registration of ccTLD might have some additional requirements.
Apart from TLDs there are second-level domains (SLD or 2LD) that look like mydomain.co.uk. All of them are ccTLDs with defined activity types (commercial and general UK).
There also are so-called “subdomains” also referred to as third-level domains. If you register mydomain.co.uk and create sub.mydomain.co.uk, it will be a third-level domain.
It is not forbidden to use higher level domains if you want to. Though it is not a common practice.
How to choose a domain name?
That’s a complex question we give in-depth explanation for it in this article.
Domain name registration limitations.
- Domain name size limitations. Each part (except for the TLD) should not be shorter than 1-2 or 3 symbols (depending on the TLD) and longer than 63 symbols.
- Different alphabet type limitations for different TLDs (Arabic, Cyrillic, Latin, etc.). Some TLD Registries allow using only one and others choosing out of several. All of them allow using digits and hyphens.
- Some limitations can be set by ccTLD Registries (unacceptable names, trademarks and other).
- Hyphens can’t be placed as the 3rd and/or 4th symbol for a domain name (do—main.com). This restriction works for all TLDs and registrars due to IDN domain specifics.
These rules are effective worldwide with minor differences. We advise to review domain registration rules before registering a ccTLD domain.
