What Is Tea? Everything You Need to Know

Tea is a drink made by infusing the leaves of the tea plant, Camellia sinensis, in hot or cold water. After water, it's the most widely consumed beverage on Earth — people drink an estimated 2 trillion cups of it every year.

Where Tea Comes From

All true teas (white, green, yellow, oolong, black and pu-erh) come from the same plant, Camellia sinensis. The differences between them come entirely from how the leaves are processed after harvest: how much they're withered, oxidized, rolled and dried.

Legend traces tea's discovery to ancient China around 2737 BCE, when leaves from a nearby tree are said to have blown into a pot of boiling water. Whether or not that story is literally true, tea drinking has been documented in China for thousands of years and later spread across Asia, the Middle East and eventually the world.

Top Tea-Producing Countries

China and India together account for roughly 60% of global tea production. For a closer look at each region, see where tea is grown.

Who Drinks the Most Tea?

Consumption doesn't track production. Turkey, Ireland and the United Kingdom top global per-capita tea consumption, while China — the largest producer — ranks much lower on a per-person basis. For more on one of the biggest tea-drinking cultures, see what makes Turkish tea special.

The Six Types of Tea

All six types below start as the same leaf; processing is what sets them apart.

• White tea: The least processed type, made from young buds and leaves with minimal withering and drying. Light, delicate flavor; more in our white tea guide.
• Green tea: Heated quickly (steamed or pan-fired) to stop oxidation, keeping the leaf green and the flavor grassy or vegetal. See the main types of green tea.
• Yellow tea: Rare and similar to green tea, but with an extra "smothering" step that gives it a mellower taste. Here's what yellow tea is in more detail.
• Oolong tea: Partially oxidized, landing somewhere between green and black tea in flavor and color. Start with oolong tea basics or jump to our best oolong tea picks.
• Black tea: Fully oxidized, giving it a dark color and a bold, robust flavor. This is the base for chai and English breakfast blends. Our guide to types of black tea covers the main varieties.
• Pu-erh tea: A fermented, aged tea from Yunnan, China, known for its deep, earthy flavor. Our pu-erh tea guide goes deeper.

Curious how any of these are grown and processed? See how tea is made from start to finish. Choosing between the two most common? Our black tea vs. green tea comparison breaks down taste and caffeine.

Health Benefits of Tea

Most tea research has focused on green tea, though findings often apply broadly across true teas. Tea contains antioxidant compounds called polyphenols (including catechins like EGCG in green tea), along with small amounts of minerals and vitamins.

Some studies suggest regular tea drinking is associated with support for heart health and healthy aging, and researchers continue to study polyphenols' potential role in reducing oxidative stress; the NCCIH's green tea overview summarizes current research on cholesterol and heart disease risk. Research into tea and cognitive decline (such as Alzheimer's and Parkinson's) is ongoing but still early — tea is not a proven treatment or prevention for these conditions.

Side Effects and Precautions

Tea naturally contains caffeine (except herbal infusions, which aren't true teas), roughly 14–60 mg per 8-ounce cup depending on type and brew strength. If you're sensitive to caffeine, pregnant, or manage a heart condition, stick to lower-caffeine options or check our guide to teas low in caffeine. Drinking very large amounts of tea can also interfere with iron absorption.

FAQ

Is tea just Camellia sinensis, or does "tea" include herbal infusions?

Strictly speaking, "tea" refers only to drinks made from Camellia sinensis. Chamomile, hibiscus and similar drinks are herbal infusions, sometimes called tisanes, though the word "tea" is commonly used for both.

Which type of tea has the most health research behind it?

Green tea has the largest body of research, mostly because of its antioxidant catechin content, but white, oolong and black teas share many of the same base compounds.

Does tea have caffeine?

Yes. All true teas contain caffeine, though amounts vary by type and brewing method — green and white teas are generally lower than black tea.

The Bottom Line

Tea is simply the infused leaf of Camellia sinensis, and the six main types are all made from that one plant through different processing methods. It's enjoyed worldwide both for its flavor and for antioxidant compounds that may offer modest health benefits — but it isn't a cure for anything, just a genuinely good daily habit.