Tourist Permit: As a Canadian or American, when you arrive into Mexico you are given a Tourist Permit which allows you to remain in Mexico for up to six months (180 days) without working.
FM-3 Non-Immigrant Visa: There are many different types of FM-3 (officially known as no inmigrante visitante) visas, including designations necessary to conduct business and work in Mexico.
For a rentista visa, the most common type of FM-3 among Canadians and Americans is designed for those who wish to live at least part-time in Mexico, but do not necessarily intend to make it their permanent home. To qualify for this type of FM-3, you have to demonstrate the financial ability to support yourself while in Mexico on funds you’ve earned (or are earning) elsewhere. The requirement is to prove you have a monthly income of $1,300 for an individual, plus about $500 for each dependent.
The specifics change from time to time, so be sure to check with your nearest Mexican consulate for the most up-to-date information.
FM-2 Immigrant Visa: The FM-2 (inmigrante) visa is designed for those who intend to permanently reside in Mexico or seek Mexican citizenship. With a FM-2, you have many of the same rights as a Mexican citizen (except voting) including the ability to work. For a FM-2 you must show a higher monthly income.