The difference between trademark serial numbers and registration numbers mainly lies in the trademark status and application stage they represent.

The trademark serial number is a serial number generated during the trademark registration application process and is used to identify the order of trademark registration applications. After a trademark registration application is submitted, the trademark serial number will be displayed on the trademark office's query report to identify the uniqueness of the trademark registration application.

The trademark registration number is the registration number issued by the Trademark Office for the trademark after the trademark registration application has been reviewed. This number is unique and represents the identity of the trademark. It can be used to query information related to the trademark, such as trademark applicant, trademark status, trademark category, trademark validity period, etc., and can also be used to handle related business.

In general, the trademark serial number is the identifier during the trademark registration application stage, while the trademark registration number is the identifier after the trademark registration is successful.