- For goods: the mark must appear on the goods, the container for the goods, or displays associated with the goods, and the goods must be sold or transported in commerce.
- For services: the mark must be used or displayed in the sale or advertising of the services, and the services must be rendered in commerce.
When you apply for federal trademark registration questions are asked about your mark and commerce, in connection with the goods and/or services indicated in your application.
In practical terms: "Use in Commerce" could mean that your product (goods) or service was sold outside of the state in which it originates or was advertised out of state.
The USPTO defines "Interstate Commerce" as sending goods across state lines with the mark displayed on the goods or the packaging for the goods. "Interstate Commerce" for services involves offering a service to those in another state or rendering a service which affects interstate commerce (e.g. restaurants, gas stations, hotels, etc.).