If you are a holder of a valid foreign passport (except USA) and planning to travel to Canada in the near future you will be required to apply for a Canadian eTA. eTA Canada or the Electronic Travel authorization was created to allow foreign citizens to enter Canada by air. Travelers can easily apply for their eTA online if they wish to reside in Canada for up to 6 months. You may apply for your eTA if you plan on entering Canada for one of the following reasons – business, tourism, transit or medical purposes. In order to apply for an eTA, you must hold a valid passport, you must be at least 18 years old and travel to Canada by air. If you have applied for an eTA you do not need to apply for a Visa, the same applies for the Visa, if you have applied for a regular visa you do not need to apply for an eTA.
If you have chosen to travel by car, train, bus or ship you must check with the officials if you are eligible to enter Canada on your eTA. In most of the cases, if you wish to enter by other means than a plane you will need to hold a visa.