“A trademark or trade mark or trade-mark  is a distinctive sign or indicator used by an individual,business organization, or other legal entity to identify that the products orservices to consumers with which the trademark appears originate from a unique source, and to distinguish its products or services from those of other entities.” Wikipedia
Trademarks are more necessary than you think.
According to law, trademarks are a form of property. While you can attach a trademark symbol to your product name or packaging and use it in the market legally, the amount of protection that affords you is limited. The only way to truly protect your intellectual property, or products is by registering your trademark with theU.S. Patent and Trademark Office.
State Versus Federal Registration
There are two options when registering a trademark. You can register with at the state level and the federal level. Registering with your state only provides a limited jurisdiction to enforce the copyright, often limited to a particular geographic area. Some people choose this option for economic reasons, as it is a more affordable option. However, to truly protect your product and brand, registering your trademark with the U.S. Patent and Trademark Office is by far the smartest option. A trademark can last indefinitely, as long as market requirements are met.
What are “Common Law” rights?
Under “Common Law” a business that has been using a product name or image in a market for an established period of time can be protected by law, but the process is considerably longer and there is no guarantee of a positive outcome. Protecting your product and investment with a trademark is always the best course of action.