If you live in Canada, your spouse can visit you if they are from a visa-free country such as Japan, Mexico or Sweden. If not, they can acquire a Visitor Visa (also known as a Temporary Resident Visa). They will need to meet the same eligibility requirements as all other applicants, which includes:
Having enough funds for the trip
Being in good health
Having no criminal convictions
Demonstrating that the trip is only temporary
Possessing a passport (or another valid travel document)
If your spouse wants to visit you while the Spouse Visa application is being processed, they still need to obtain a Visitor Visa. However, this is often more difficult after the sponsorship application has been made, so it is safer to avoid this.