The move follows Parliament’s approval of Bill C-45 in June, which came into effect this week.

Here’s what you need to know.

Only a few aspects of the law will be dictated at the federal level. This includes the limits to possession—adults will be permitted to have up to 30 grams of marijuana and as many as four plants per household. Medical marijuana, which has been legal since 2001, will remain in place.

As of Wednesday, only the marijuana flower, seeds, plants, and cannabis oil are available for sale. Edibles and concentrates will not be permitted until next year. Legal marijuana has lower levels of THC, the principal psychoactive ingredient in marijuana that makes the user feel high. The rest of the regulations will be determined province to province, including where marijuana can be sold and consumed.

In most provinces, the legal age for the purchase and use of marijuana is 19. In Quebec, the age limit is set at 18, but the newly elected government has pledged to raise the age to 21, as the New York Times reports. Marijuana will now be sold in government stores or private stores or a mix of both, depending on the province. Users can also buy marijuana online and have products delivered to their homes. For the time being, it will not be sold in bars or restaurants.

In provinces such as Ontario, British Columbia, and Alberta people are allowed to smoke marijuana wherever cigarette smoking is permitted. In Halifax, there will be designated smoking areas. With jurisdiction delegated to the province level and below, some municipalities and even hotels and landlords are implementing their own rules and regulations around marijuana use—with some banning it entirely.

The piecemeal approach to the law is already causing some confusion among Canadians and users. However, financially, the legalization of marijuana is due to be a boon to the economy and cannabis startups. Because it is legal at the national level, businesses dealing in marijuana will be able to use banks and trade stocks like any other business. They will also be able to sponsor peer-reviewed medical studies. The industry is expected to be worth $6.5 billion in annual sales, according to one estimate.