There are many different types of tea but they all fall under 2 categories: true teas and herbal teas.
These are all teas made from the tea plant called Camellia sinensis. There are only 5 true teas in the world: black tea, white tea, green tea, oolong tea, pu-erh tea.
These teas take a long time to harvest and process, so that the tea leaves fully oxidize. This creates the dark color of the tea.
Flavour: strong, earthy flavours. May sometimes have a nutty or sweet taste.
Examples: English/Irish breakfast teas, darjeerling tea, lapsang souchong
Green teas are primarily from East Asia and don't have a lot of processing, but still more than white teas. The tea leaves are usually fried or steamed like, and the length of time gives it different tastes.
Flavour: earth and grassy to floral tasting. Fried teas tend to taste nuttier and earthy, while steamed teas taste more like vegetables or herbs.
Examples: sencha, gyokuro, genmaicha, matcha, longjing
This is the least processed of the true teas. This is made only using the youngest buds and leaves of the tea plant.
Flavour: a little sweet with many aftertastes (depending on the type). They can have floral, nutty, or fruity tastes.
Examples: Silver Needle, White Peony
This tea mainly comes from China. It is semi-oxidized and dried over bamboo mats. The length of time they are dried will determine their flavour. They are then fried and packaged.
Flavour: some oolong teas are very strong with earthy flavours, while others are lighter tasting with a more floral flavour.
Examples: Iron Goddess of Mercy, Wuyi oolongs (Da Hong Pao/Red Robe tea), Milk Oolong tea
This tea is heavily oxidized and aged for a long time (sometimes years). The leaves are piled and covered with linens so that bacteria helps to age and flavour the tea.
Flavour: strong taste with woody and earthy flavours.
Examples: there are not many huge brands of pu-erh tea, but try to find one that had been aged for at least 4-7 years (this gives it more flavour).
These are teas that use one of the 5 true teas and add other flavour to them. The most famous of which are Earl Grey, Orange Pekoe, Red Rose, Masada Chai, jasmine tea
These are made from plants that are not the tea plant (Camellia sinensis). The parts of the plant will be boiled and are caffeine free.
This comes from the chamomile flower and is known for its calming abilities. It blends well with lemongrass and honey.
Flavour: similar to green apples
This tea comes from the rooibos flower in South Africs. Known for its redness it is also packed with nutrients.
Flavour: a bit sweet and sour taste
Made from mint leaves that gives a tingling cooling sensation. This can help with relaxation.
Flavour: minty with a bit of an aftertaste
A tea made from the hibiscus plant primarily grown in tropical places. It udually has a pinkish colour.
Flavour: sweet and tart
Tea made from the roots of a licorice plant. Thought to be good for upset stomachs.
Flavour: tastes like licorice, and has a slightly spicy and minty taste.
This tea is made from the buds of a Lavender plant. Said to be good for helping one sleep.
Flavour: usually taste like rosemary and mint, though they can often have an earthy and floral aftertaste as well.
This tea is made from the Linden flower and is very popular in Latin America. Similar to chamomile and has similar relaxing effects.
Flavour: floral taste with a bit of licorice aftertaste