Camellia sinensis is the species of plant all teas, aside from herbal teas, are derived from. Herbal teas are actually specific dried flowers and herbs and are not actually "tea." Both tea and herbal teas can be brewed loose using a strainer or by using convenient tea bags, and enjoyed in delicious hot or iced drinks.

The three main varieties of the camellia sinensis tea plant are the India, or Assam, the China and the hybrid. India tea is large-leafed and grows well in lower altitudes, while China tea is small-leafed and grows well in higher altitudes. Hybrid tea mixes quantities of both China and India teas. The four main types of tea derived from India, China and hybrid teas are oolong, green, black and white.

White tea is the rarest and least processed tea. Its taste can be very grassy at times. Processing tea usually involves oxidation, or fermentation. The oxidation occurs when enzymes in the tea plant are either bruised, broken or crushed so that the enzymes are exposed to air. White tea is not oxidized at all, but just left to dry as is. This air drying process is called withering.

White tea gets its name from its silver-colored dried buds with their white, thread-like growths. White tea has the least amount of caffeine and the highest amount of antioxidants of the four main types of tea. Silver Needle is a type of white tea with a delicately sweet flavor.

Black tea is the most popular tea worldwide, but it does not have as many antioxidants as the other types of teas and it contains the most caffeine. Black tea is fully oxidized. The leaves are rolled to break up the surface so that the leaves are open to air. When the leaves are fully oxidized they turn completely black, hence the name black tea. Keemun black tea is said to have a chocolate-like flavor. Darjeeling and Ceylon are other examples of black tea.

Green tea is closer to white tea than black tea as it is non-oxidized. The difference between white and green tea is that green tea uses rolled leaves and not the buds. The grassy taste of green tea is very similar to that of white tea and green tea is low in caffeine and high in antioxidants compared to black tea. Jin Xian Te Jian and Hojicha are types of green tea.

Oolong tea is often considered the most difficult tea to process as oolong leaves are only partially oxidized. The leaves cannot be broken or crushed, as full oxidation would occur, so they must only be bruised. Bruising tea for oolong usually occurs by throwing the leaves in baskets so only the edges of the leaves are opened to air. Oolongs can be more like black teas or more like green teas in their fermentation. Pouchong and Formosa are two kinds of oolong tea.

Decaffeinated black teas are popular in Western cultures. The United States has approved both the use of carbon dioxide and ethyl acetate in the process of removing caffeine from black tea. The American Medical Association (AMA) has stated that up to seven cups of black tea a day is not an excessive amount of caffeine consumption for most adults.

Herbal teas, though not actually from the tea plant, are often very flavorful. Herbal teas can be made from many different flowers and herbs. Herbal tea varieties such as peppermint, peach, strawberry and lemongrass are popular tea alternatives.