India, China and Japan are the largest markets for quality whole leaf tea. Tea bags contain fannings and dust, the lowest quality byproducts of tea production. Try a single estate TGFOP and you’ll never want to drink tea from a bag again.

Chinese tea is again a whole different world from Indian tea, and has a much broader spectrum of complexity. You could spend a lifetime learning about Chinese tea.

My knowledge of this from a long time ago and narrow, but I can give you a rough picture.

Different countries do buy different types and qualities of tea. The US is big market for low quality (dust, stalks) tea for tea bags.

Countries that like strong sweet tea with lots of milk buy tea that is low grown (i.e. lower elevations) and processed using the "cut, torn curled" process rather than the older "orthodox" process. High grown (on mountains) tea is better for those who drink it without milk.

Leaves do tend to be higher quality and they have grades reflecting the size of the pieces. There is a standard system which is marked on some types of tea.

It is usual to pluck two leaves and a bud. Plucking more would add a lot of stalk which lower quality. Plucking or using just a bud produces a very delicate flavour (sivlertips). High grown silvertips is good with

Most tea is blended so will contain a mix of different things.