If you intend about vacation or visit to the Canada, you need to get Canada Visa ETA before you travel in the USA. Type of Canada visa you need depends mainly on you are going on which purposes and apply lots of visa such as Electronic Travel Authority (ETA) or on a tourist visa or a Sponsored Family Visitor visa. ETA allows you some entire period that you want to stay in the Canada.
Electronic Travel Authority (ETA) is electronic visa and main thing is can not get a stamp in their passport or a label, but do not worry because Australian immigration officials have their visa records.
You can apply ETA for Canada tour but 34 eligible countries under the VWP. If you country listed in VWP definitely you apply online visa ETA Canadian. You have to pay online fees for visa so apply over the Internet.
However, you can apply for a tourist visa the duration is usually 3 or 6 months, but may be extend to 12 months if you have any reason to stay here. Tourist visas application apply online also.