Apply for Super Visa if you want to visit your children or grandchildren.
A Super visa lets you visit your children or grandchildren for up to 2 years at a time. It's a multi entry visa that provides multiple entries for a period up tp 10 years.
If you don't need a visitor visa to enter Canada, you can still get a super visa to stay in Canada for up to 2 years. If your application is approved, IRCC will issue you a letter to give to a border services officer when you arrive in Canada.
If you travel by air, you may also need to apply for eTA, separately to allow you to travel and enter Canada. The eTA will be linked to your passport, so you need to travel with the passport you used to apply for eTA, and your letter to facilitate your travel to Canada.