The system for domain name registration generally operates on a first-come first-served basis and no two domain names can be exactly the same. It is strongly advisable to search the domain name databases and to check that the same or a similar domain name doesn't already exist or exists in another top-level domain.
The easiest way to check if a domain name is available is at one of the companies that have been approved to register domain names. A list of accredited and accreditation-qualified registrars can be found on the ICANN (Internet Corporation for Assigned Names and Numbers) web site: www.icann.org
It is also a best practice to do a trademark search before you register your domain name, since domain registrars generally do not check if a requested name violates an existing trademark. Therefore, if you register a domain name that conflicts with someone else’s trademark, you could lose the right to it if the trademark owner takes legal action against you.