A trademark is a word, phrase, symbol or design, or combination of them which identifies the source and quality of a business product. For example, Nike identifies a particular brand of athletic shoe. A service mark is the same as a trademark except that it identifies and distinguishes a service rather than a tangible product. The terms trademark or mark are used commonly to refer to both trademarks and service marks. Trade names or business names are used to identify a particular company or corporation as a whole.
Trademarks are names that identify a business's goods or services in the marketplace.
Business names can become trademarks when they are used in the marketplace to identify a product or service. As an example, the computer giant Microsoft uses the Microsoft name both as its corporate name and also as a trademark. Registering a business name through state corporate name registration or state fictitious business name registration secures the right to use that business name to transact business, but it doesn't create the right to use that name in the marketplace as a trademark. If you advertise your products or services under your business name, your rights to that use derive principally from trademark law. Trademark ownership arises from use.