Ummm....not sure if all of the info. above is 100% accurate.........An International Driver's License/Permit (IDL or IDP) is valid in over 150 countries and (unless you were referring to Europe/EU specifically and if they have different rules) many countries want to see them in conjunction with the driver's license from your country of origin.
"The IDP is valid in all countries that have signed the 1949 Convention on Road Traffic and is recognized in many countries that are not signatories to the Convention. You may be required to have a valid IDP to drive in some countries and some foreign car rental agencies may require you to have one to rent a car."
They generally cost between $15-$20 US/CDN and may be valid for up to one year. It's recommended that anyone wanting to drive in another country, check out the rules and regs. via the High Commission, Embassy, Consulate (or whatever the term used) in the respective country.
Here are some helpful links: http://travel.gc.ca/travelling/documents/international-driving-permit
https://treaties.un.org/pages/ViewDetailsV.aspx?&src=TREATY&mtdsg_no=XI%7EB%7E1&chapter=11&Temp=mtdsg5&lang=en
As far as things working the same in Ontario as BC, our experience in Ontario was that no one at the Drivers Centre asked my husband to hand in his licenses and they obviously knew he was licensed from another country as we had to provide a notarized letter from the licensing authority in his home country so that he could get credit for his many years of experience and do the G1 and G2 within a week of each other.
We didn't think to ask about handing back his licenses because we both thought he would need them when he travels back and forth (due to some family obligations). On the day my husband and I went to do his road test over 85% of the people in the office that day doing their tests were also folks landed from other countries (I know because I did ask the registration clerk). I would think that the Driver Centers here in Ontario have experience with this unless they were simply too busy and forgot. That's always possible too!