The meaning of the Dutch word thee is just as broad as tea, and can include black (zwarte thee), green (groene thee), herbal (kruidenthee), fruit (fruitthee) and other teas.
Annually, the Dutch consume about 101 liters of tea per capita (i.e. four times that of the Americans, but only a third of what the British drink).
Compared to the British, the Dutch like their tea quite weak, and they usually drink it without milk. If you order tea in Holland, you'll generally be presented with a glass of hot water and a bowl that contains a wide selection of teas.
The best place to buy tea in Amsterdam is at Tea Bar, where you'll find some 60 varieties of loose leaf teas, which can be combined to taste. It's a gorgeously designed hotspot, and what's really special is that you can try before you buy. Simon Levelt has been trading in teas for 200 years and offers 200 interesting varieties from all over the world. They have stores all over the Netherlands. For something a little more exclusive, you'll have to visit Kampen: De Eenhoorn has a special relationship with Taiwanese tea master Madame Tseng, one of only ten recognized tea masters in the world, and access to private gardens in China, Taiwan and Sri Lanka.