There can be confusion about the differences among trademark name, company name, and domain name. Likewise, people wonder whether having one of the foregoing protects them against claims of trademark infringement.
A trademark name (or simply a "trademark") can be a word, symbol, color, sound, or other things that serve to identify the source of goods or services. A trademark can be a company name or a domain name.
However, a company name or a domain name is not necessarily a trademark.
A company name can be for a corporation or limited liability company (LLC). A Secretary of State can authorize the formation of a corporation or LLC with a name. Generally, when the Secretary of State authorizes the use of a name, it merely means that no one else in the State has registered the exact same name.
The authorization does not mean you own the trademark to the company name. Nor does it mean that the company name does not infringe another's trademark.
Therefore, even if you form a corporation or LLC with a name, you may still need to register the name as a trademark.
Fictitious Business Name (dba)
Similarly, like with a corporate/LLC name, when you register a fictitious business name with you local county clerk, the registration simply means that no one else has registered the identical name.
The fictitious business name registration does not give you trademark rights.
A domain name is a place in the Internet where others can access your website.
Frequently, the domain name is chosen to mimic the company name so that the domain name is easy to remember.
But registering a domain name does not mean you own the trademark to the name. Nor does it mean you are not infringing another's trademark.
Like with a company name, even though you own a domain name, if you want trademark protection for the domain name, you may wish to register the domain name as a trademark.