Foreign law means the law of countries other than Canada - for example, the law of Japan that governs the conduct of people and organizations within the country of Japan.
International law governs the conduct of nations or countries' governments when they interact with each other. Treaties (nation-to-nation agreements) fall under this category.
Comparative law is the study of the differences between laws of various jurisdictions. These jurisdictions can be provinces within one country (for example, Ontario's employment law versus Alberta's) or they can be different sovereign nations (for example, US immigration law versus Canadian).
Law and Justice Around the World by 1) The law on various topics can differ radically between different countries, even if the countries seem to have similar cultures or similar legal systems.
a) The US and Canada, for example, have very different laws when it comes to the status of cannabis: in the US, it remains illegal on the federal level even for medical use, while in Canada it is legal for medical and recreational use on the federal level.
2) English translations of foreign law are not always available. If you can't find an English translation, ensure you use multiple sources of reliable information about the foreign law in question to verify that your understanding is correct.
3) Start broad and general, not narrow and specific. Read background material on the countries, regions or legal systems you're interested in. This will give you context, and help you develop the right vocabulary for developing search terms. Encyclopedias are a good place to start.
Check out Osgoode Hall Law Library librarian Sharon Wang's in-depth research guide on foreign and comparative law for more guidance, including links to websites for finding foreign law, recommended reading on legal theory, and guidebooks on research methodologies.