An International Driving Permit (IDP) restates the details on your provincial driver's license across several languages, so it can be read and verified by people who don't work in English or French.
The format traces back to international road traffic agreements that set out a common layout, so a license issued in one country would make sense to an official somewhere else. It doesn't replace your provincial license — it's a companion document, always shown together with the license it translates.
For a Canadian traveler, that mostly matters once you're outside North America. Your Ontario, British Columbia, or Quebec license is already written in English or French, both of which are widely understood, so an IDP earns its keep in places using other scripts and languages — Japan, Thailand, the UAE, and similar destinations.
Requirements shift by country and change over time, so treat an IDP as part of your prep, not a guarantee. Entry, driving, and car-rental requirements can change and vary by destination. Always confirm current rules with the relevant embassy, consulate, or local authority before you travel.