You will record places for just about everything: where people lived, worked, were born, married, died, came from, and went to. Discovering these places is important, since the civic and other historical records of those places may provide information about your family. Place names, like surnames, can have many variant spellings and pronunciations.
Places present historical challenges, since the names of many places have changed over time. For example, Ville-Marie became Montréal, and York became Toronto. Other places have "moved" from one province or country to another as geopolitical boundaries have shifted because of treaties, accords, or wars. Although Canada is comparatively young, it has had its share of changing boundaries as districts and then provinces were established.
In your research, rely on gazetteers, maps and atlases, both modern and historical, which describe or map the places you are researching. Every Canadian province and territory has gazetteers, giving both old and new names that help you identify and locate various places. These useful works may be found in libraries and archives, and some have been reproduced on the Internet. See Where to Search: Places for more information.