What is a TLD (top-level domain)?

A top-level domain (TLD) is the highest level in the internet's domain name system — the part of a web address that comes after the final dot. In example.best, the TLD is .best; in example.com, it's .com.

TLDs fall into a few families: generic TLDs (gTLDs) like .com, .org and .best; country-code TLDs (ccTLDs) like .fr or .ai; and sponsored or specialised TLDs. New gTLDs are introduced by ICANN in periodic application rounds.