What is the difference between a citizenship certificate and a Canadian passport?

These two documents serve different roles and are not interchangeable. A citizenship certificate confirms your legal status as a Canadian citizen, but it does not let you cross international borders and is not photo ID.

A passport, by contrast, is a secure travel document that you use to enter and leave countries. In practice, many people apply for a citizenship certificate first to establish proof of citizenship, then use that proof to apply for a passport. Keeping both up to date ensures you can both prove your citizenship and travel without problems.