Tea comes from the evergreen shrub called Camellia sinensis. There are two varietals: Camellia sinensis var. sinensis (Chinese tea) and Camellia sinensis var. assamica (Assam or Indian tea). All tea comes from this plant.
Thousands of tea estates around the world produce tea. Each estate masterfully crafts a unique tea all originating from the Camellia sinensis plant. It is the process for picking and drying that determines the type of tea; green, yellow, white, oolong, black, and pu-erh.
Red tea processing
Red Tea or Oolong tea is semi-oxidized, so the leaf is allowed to sit for maybe 2-4 hours, before being heated up to halt oxidization. The amount of oxidation affects the flavour and appearance of the tea. Longer oxidization results in a darker oolong which is more similar in taste to a black tea, while shorter oxidization makes it more similar in nature to green tea. When steeped, Oolong tea produces golden or light brown tea with a very delicate flavour resembling neither black nor green tea.