What is Tea?

The thousands of teas on the shelf, from a brisk English breakfast to a grassy Japanese green, all trace back to that one plant.

What follows from that single fact is surprisingly deep. The same leaf, handled differently, becomes white, green, oolong, black, or pu-erh tea, each with its own color, flavor, and caffeine level. Here is what tea actually is, where it comes from, how the types differ, and how to find the one you will reach for every day.

What is tea, exactly

By definition, tea is the infusion of leaves from a single evergreen shrub, Camellia sinensis. If the leaves in your cup did not come from that plant, what you are drinking is not technically tea, no matter what the box says. That one rule is the key to understanding everything else.

The plant comes in two main varieties that shape the teas made from it. Camellia sinensis sinensis is the smaller-leafed, cold-hardy variety associated with China, and Camellia sinensis assamica is the larger-leafed, heat-loving variety from the Assam region of India. Most of the world's tea is some expression of these two, grown in different climates and crafted by different hands.

So when you hear white, green, oolong, black, and pu-erh described as separate teas, remember they all come from the same plant. The differences come entirely from what happens after the leaf is picked.

A short history of tea

Tea's story stretches back thousands of years, and its origins are steeped in legend. One of the most enduring tales of a Chinese emperor enjoying a bowl of hot water when leaves from a nearby Camellia sinensis tree drifted into it by chance. Whether or not the story is true, the larger point is: tea began in China, where it was cultivated, refined, and celebrated for centuries.

Until the 1800s, China produced nearly all of the world's tea, closely guarding the knowledge behind its cultivation and processing. Over time, tea spread well beyond its borders. Today, it is grown in around 40 countries, with China, India, Kenya, Sri Lanka, and Turkey among the world's leading producers. Each region's climate, soil, and growing traditions bring distinct character to the leaf, creating the remarkable range of flavors we enjoy today.

If you'd like to dive deeper, our guide to the history of tea explores how a single plant from China became one of the world's most beloved daily rituals.

Tea or tisane: the real difference

The drinks we casually call "herbal tea", chamomile, peppermint, hibiscus, and rooibos, are not actually tea. They contain no Camellia sinensis. The correct word for them is tisane, an infusion of herbs, flowers, fruits, roots, or bark in hot water.

Because tisanes contain no tea leaves, they are naturally caffeine free, making them the natural choice for the evening or for anyone sensitive to caffeine. They are prepared much like tea and can be served hot or iced, but technically, they sit just outside the definition. In that sense, the phrase "herbal tea" is a bit of an oxymoron: it is either tea or tisane. Our full range of herbal tisanes shows just how wide the world of caffeine free options runs.

If it does not come from Camellia sinensis, it is not tea. It is a tisane.

How one plant becomes every type

If every true tea comes from one plant, why does black tea look and taste nothing like green? The answer is oxidation, the single most important word in understanding tea. Oxidation is the natural process in which enzymes in the leaf react with oxygen. Once the leaf is bruised or exposed to air, the same browning you see when a cut apple sits out.

Tea makers control that reaction to create each style. Stop oxidation early by quickly heating the leaves, and you preserve a fresh, green character. Let it run fully, and the leaf darkens and deepens into a bold, malty cup. Green tea is essentially unoxidized, black tea is fully oxidized, and oolong sits anywhere in between. It is a single spectrum, from light to dark, determined by how the leaf is handled. People often confuse this with fermentation, so our guide on oxidized versus fermented tea clears up where pu-erh fits.

The main types of tea

There are five true tea types you will most often encounter, plus the tisanes that round out any good tea shelf. Here is the quick map, then a closer look at each.

Type	Oxidation	Caffeine	Flavor
White	Minimal	Low to moderate	Delicate, floral, sweet
Green	None (unoxidized)	Moderate	Fresh, grassy, nutty
Oolong	Partial (semi)	Moderate to high	Floral to roasted, complex
Black	Full (100%)	Moderate to high	Bold, malty, brisk
Pu-erh	Post-fermented	Moderate to high	Earthy, deep, aged
Herbal and rooibos (tisane)	Not a true tea	caffeine free	Varies widely

White tea is the least processed of all. It is made from young leaves and unopened buds, traditionally harvested for a short window each spring in Fujian province, China, where the silvery down on the buds, called Hao, gives the style its name. The cup is light, sweet, and floral. Explore our white tea collection if you enjoy gentle, delicate teas.

Green tea is unoxidized, with the leaves heated soon after harvest to lock in their color and fresh character. Chinese greens are typically pan-fired for a toasty edge, while Japanese greens are steamed for a brighter, more vegetal taste. The result is grassy, clean, and sometimes nutty, and our green tea collection spans both traditions.

Oolong tea falls in the middle, semi-oxidized, ranging from barely to nearly fully oxidized. The leaves are withered, partly oxidized, and often finished over charcoal, which is why oolongs range so widely, from light and floral to dark and roasted. Few teas reward exploration as much as our oolong collection.

Black tea is fully oxidized, which gives it the deep color and bold, malty body most of the West grew up on. In China, it is often called red tea for its reddish brew. It stands up to milk, sugar, and ice better than any other type, and it anchors our black tea collection.

Pu-erh tea is the outlier, a post-fermented tea from the Yunnan province of China, made from a broad-leafed varietal and famous for aging like fine wine. Some pu-erhs are cellared for decades, deepening into an earthy, smooth cup unlike anything else. It is the best tea most people have never tried, and our pu-erh collection is a fine place to start. For the full story, see what pu-erh tea is.

Rounding things out are the tisanes: rooibos, a naturally sweet, caffeine free plant from South Africa, and the broad family of herbal infusions made from chamomile, peppermint, ginger, hibiscus, and more. Not true teas, but a cornerstone of any cup collection, especially after dark.

Does tea have caffeine?

Yes, every true tea contains caffeine, because Camellia sinensis produces it naturally. How much ends up in your cup depends on the type of tea, the leaf, and how you brew it. As a rough order, white and green teas tend to sit lower, while oolong, black, and pu-erh tend to run higher, though there is plenty of overlap.

Even at the high end, tea is gentler than coffee. A cup of black tea usually lands well below a cup of coffee, and it delivers its lift more smoothly thanks to an amino acid called L-theanine, which softens the edge. If you want exact numbers, our breakdown of tea caffeine content lays out the ranges by type. And when you want none at all, the tisanes have you covered.

Is tea good for you?

Tea has been valued for its wellbeing benefits for thousands of years, and modern research is beginning to explain why. True teas are known to be rich in polyphenols, a group of natural antioxidants that includes the catechins found in green tea and theaflavins formed when black tea oxidizes. These compounds are widely studied for their role in supporting heart and metabolic health.

Tea also contains L-theanine, an amino acid that promotes a calm, focused alertness. Paired with tea's moderate caffeine, it is what gives a cup its steady lift without the jitters coffee can bring, which is why many people find tea a more even source of energy throughout the day.

None of this makes tea a medicine, and it's important to keep the research in perspective. Studies continue to explore tea's potential benefits, but no single cup is a guarantee. What tea is known to offer is a simple daily ritual, a hydrating beverage rich in plant compounds. The best tea is the one you genuinely enjoy drinking, because that's what turns an occasional cup into a lasting habit.

How tea is brewed

Brewing tea is simple, but a few details separate a great cup from a bitter one. The two biggest levers are water temperature and steep time, and both vary by tea type. Delicate green and white teas prefer cooler water and a short brew, while bold black, oolong, and pu-erh teas can handle hotter water and a few minutes longer.

Start with about a teaspoon of loose leaf per cup, use fresh, filtered water, and set a timer so the leaves brew for the right amount of time. Get those basics right and even an inexpensive tea may taste far better. Our full guide on how to properly steep your tea walks through the ideal temperature and time for every type.

How to find your tea

With so many styles, the easiest way is not to overthink it. Pick a direction based on what you already like. Crave something bold in the morning? Start with black tea. Want something light and fresh? Try a green or white. Looking to wind down at night? A caffeine free tisane is your friend.

If you would rather explore across the whole range before committing, a sampler is the smartest first step. It lets you try several types side by side and learn what your palate gravitates toward, which is far more telling than any description. From there, you can lean into a single style or keep a small rotation of loose leaf teas for different moods and times of day.

Frequently asked questions