Whilst you may get the impression that the coffee shops are only for tourists, the Dutch definitely enjoy the occasional joint.
There are coffee shops not only in the tourist hotspots of Amsterdam, but in all cities and most small towns. Coffee shops don’t sell alcohol, or offer hard drugs. Those are as illegal in the Netherlands as any other country.
Due to strict tobacco laws, the joints that you smoke inside the coffee shop can’t contain any tobacco.
Smoking joints outside is frowned upon in busy places. Be respectful of non-smokers and children!