Do I need a visa for Canada?

If you are a (non-Canadian) citizen of one of the visa-exempt countries and you are travelling to Canada by air using your visa-exempt country passport, you must apply for eTA to gain authorisation to enter the border. Travellers from visa-exempt countries that enter by land or sea e.g. driving from US do not require an eTA. You will require an eTA even if you are taking a connecting flight in Canada.
First, you should check whether your country of citizenship is visa-exempt. The eTA includes travel for business, pleasure or transit for trips that are no longer than six months in duration.
If you intend to visit Canada for longer than six months then you are required to apply for the relevant type of visa that will authorise your travel i.e. studying visa, work permit, immigration visa etc.
The eTA is a process that improves border security and the information that you provide in your application is used to assess whether you will be granted permission to enter Canada using eTA. If your application is approved then it will be valid for five years, or until your passport expires. Throughout its validity, you may make numerous trips to Canada, using the same eTA.
When you complete your online eTA Canada application form, you will be required to enter personal details, your passport details and eligibility questions that will determine whether you will be granted authorisation to visit Canada through the eTA. If your application is declined, you can apply for other types of visa as an alternative to gain authorisation to visit Canada.