A top-level domain (TLD) is the last segment of the domain name. The TLD is the letters immediately following the final dot in an Internet address.
A TLD identifies something about the website it's associated with, such as its purpose, the organization that owns it, or the geographical area where it originates.
.com is seen as the strongest of domains but it is important to understand the different meanings.
.aero – Restricted for use by the international aviation community.
.biz – Restricted for use by businesses. This TLD was created because .com is used by some groups and individuals that are not businesses.
.com – Not restricted. This is the original TLD for businesses, but it has been used by many non-business groups.
.coop – Restricted for use by cooperatives.
.edu – Restricted for use by accredited educational institutions.
.gov – Restricted for use by the U.S. government.
.info – Not restricted. Intended for use by organizations that provide useful reference information.
.int – Restricted for use by organizations involved in running the Internet and organizations established by agreements among international governments.
.name – Restricted for use by individuals who want to register their own name as a domain name. This allows people to have their own personal web sites without using .com or other TLDs.
.net – Not restricted. Intended for use by organizations who contribute to the construction or maintenance of the Internet.
.mil – Restricted for use only by the U.S. military.
.museum – Restricted for use by museums.
.org – Not restricted. Intended for use by organizations such as non-profits.
.pro – Restricted for use by professionals, such as lawyers and doctors, who can pass credential checks.
.tv – For use by the television industry, particularly broadcasters.
.au – Australia
.ca – Canada
.cn – China
.co.uk – The United Kingdom
.de – Germany
.hk – Hong Kong
.it – Italy
.jp – Japan
.us – United States
There are now some additional custom domain extensions available from certain providers. For instance, for your authority site you may be able to get www.yourname.mentor or if you had started a tennis academy, www.theacademy.tennis. These are new and their SEO viability hasn’t been tested yet, so be aware of that.
Finally, make sure your domain name can be verbally communicated. You do not want to constantly repeat or spell it out.