In Canada, MPs are elected in a system known as first past the post. Electors vote for the candidate of their choice in their riding (also called an electoral district or constituency). The candidate with the most votes becomes the member for the riding. The party winning the most ridings forms the government.
The voting system doesn’t include proportional representation; in other words, a party can form the government without obtaining the most votes nationally.
However, ridings do take into account the demographic density of provinces and territories. In light of changes to the National Register of Electors, the number of MPs in the House of Commons is periodically reassessed and electoral boundaries are readjusted.