Tea is a beverage which is obtained through infusing the dried leaves of the Camellia sinensis plant. Depending on the leaves' level of oxidation, the four basic types of tea include: white tea, green tea, oolong tea and black tea. The chemical composition of tea varies depending on crop, on climate and on tea processing method. Among tea's components, we could mention theine, which is an alkaloid similar to the one found in coffee, maté, cola nuts, tannin and essential oils.