This article explains what a top-level domain (TLD) is, where it sits in the Domain Name System, and why the few characters after the final dot concentrate an outsized share of internet governance and trademark risk. It maps the categories of TLD--legacy and new generic domains, country-code domains and the repurposing problem, sponsored domains, and blockchain names that only look like TLDs--and describes ICANN's contractual hierarchy and the registry-registrar-registrant chain. It examines whether a domain name is property, why registrars are usually immune, how the GDPR darkened WHOIS and how investigators work around it, and the rights-protection mechanisms built into the new gTLD program: the Trademark Clearinghouse, Sunrise and Claims, the Uniform Rapid Suspension System, and the Trademark PDDRP. It then compares the two anti-cybersquatting remedies, the UDRP and the Anticybersquatting Consumer Protection Act at 15 U.S.C. 1125(d), and analyzes how the USPTO treats TLDs after United States Patent and Trademark Office v. Booking.com B.V. It closes with a practical playbook, worked hypotheticals, and an FAQ written for judges, practitioners, and business owners alike.