A Canada ETA is an Electronic Travel Authorisation that is required by all travellers to the country who do not come from specified countries. If you are required to apply for a travel visa to Canada, then you probably don’t need to apply for an ETA as well.
The ETA is only for travellers arriving in Canada by air or sea and will not be required for visitors crossing a land border at this time. The ETA is basically a screening process to ensure that travellers are eligible for entry into the country before they arrive.
However, the ETA is not a guarantee of entry. If a customs or border official finds any reason that a traveller should not be granted entry into Canada, they will be refused entry and returned to their country of origin even if they are in possession of a valid ETA. On the other hand, a traveller arriving in the country without an ETA will automatically be refused entry.
The application process is entirely electronic or online and you will require an e-passport as well as other travel documents in order to apply. You will also need to pay an application fee of CA$7 which is non-refundable in the event that the ETA is not approved.
You will receive confirmation of your Canada ETA via email. You do not need to print out the confirmation as the ETA will be logged on your e-passport. You should receive confirmation within a couple of days of applying although it is recommended to make application as soon as possible before you arrive in Canada.
The ETA is valid for a period of 5 years within which multiple entries into the country will be allowed. Each visit is however limited to a period of 6 months. It will be necessary to apply for an extension should you wish to remain in the country for longer than the prescribed period.