There are two types of Visitor visa for Canada:
If you plan on travelling to Canada for a holiday, family or friends visit or for business purpose, you need to apply for a Visitor visa. Visitor visa can be issued on a maximum period of 10 years and maximum period of a visit can be up to 6 months which is determined by an officer when entering the country. This visa can have single or multiple entries as Immigration service which process your visa application decides.
This visa is designed for parents, and grandparents of Canadian citizens as well of those who have permanent residence in Canada. This visa allows longer stay during one visit to Canada which is up to 2 years. Also, this is multiple entries visa so you can visit Canada multiple times during the validity of your visa. If you are eligible for this visa but plan a shorter stay in Canada, you can apply for regular visitor visa.
A tourist purpose means holiday in Australia or a visit to family, relatives and / or friends. Business purpose means participation in conferences, negotiating or market research for business matters.
Citizens of particular countries are not required to have visitor visa, they should apply for Electronic Travel Authority (ETA).
You can get in touch with me and book an appointment every working day in my office or through Skype/Viber, but first you should fill out my questionnaire.