A trademark, which is sometimes called a service mark, a trade name, a trade dress, etc, is a distinctive mark that a manufacturer uses to both distinguish their goods from others' as well and to symbolize its authenticity. A trademark can include symbols, words, designs, names, and more. And it could be a combination of a number of different design elements.
In order to be valid registration is not required on either a state or a federal level. However, if a trademark is registered at the federal level it is often accompanied by a symbol like