Definition - What does Trademark Infringement mean?
Trademark infringement refers to the unauthorized use of a trademark or a service mark on goods and services that are related or competing. Trademark infringement is likely to cause confusion in the minds of potential and existing customers about the product or services.
Justipedia explains Trademark Infringement
Trademark infringement may also occur when the trademark is similar to another one already in use. The party that legally owns the trademark may also commence legal proceedings against the person who infringes on its (trademark) registration.