The word "Tea" is commonly misused to represent just about any dried leaf or flower to which we add hot water to drink.  Tea however, is a very specific evergreen shrub (Camellia sinensis) from which it's leaves are carefully harvested and processed to produce a variety of flavors and aromas within six categories that we commonly refer to as Green, Black, White, Oolong, Yellow, and Dark teas (Pu'er).  Yes, all six of these teas come from the same plant!  But there's quite a bit of artistry and process that goes in to making each tea different.  In that, it's akin to wine making. 

Geographical variation, weather conditions, seasonal harvests, plucking technique, processing techniques, and more all go into creating differences in flavor(s), aroma, and mouthfeel.  And so, just like wine where a Merlot is different from a Pinot Noir or even where one Merlot is different from another Merlot, the same can be said about tea. An Assam Black is very different from a Ceylon Black and there are significant differences from one Assam to another depending on the conditions that went in to growing, harvesting, and producing the specific tea.  The magic is in the variety and the discovery of those differences.

"Herbal Tea" and/or "Tisane" are words used to describe beverages that use leaves, bark, roots, berries, seeds, and spices that, like tea, are added to hot water. Common tisanes include mint, chamomile, and rooibos.  But none of these are actually tea.  Who knew?