Tea comes in many varieties. Officially only the Camellia Sinensis plant, it is common for other plants and herbs to be steeped in hot water.
Tea
 benefits nearly every organ system in the body. It is cardioprotective,
 neuroprotective, anti-obesity, anti-carcinogenic, anti-diabetic, liver 
protective, and beneficial to blood vessel health.
Behind water, 
it is the second most consumed beverage in the world. On any given day, 
over half of the American population drinks tea.
Growing 
conditions vary resulting in a number of distinctive leaves. 
Surprisingly, it is the type of processing that determines the major 
difference between the four most common types: black, green, white, and 
oolong. All of these factors combine to influence both the flavor and 
nutritional content.
Most Common Teas
Black tea: The most common type with the highest caffeine, made with fermented tea leaves.
Green tea: Made with unfermented leaves, it has a high concentration of the catechin, EGCG.
White tea: It is the least processed and made from the new growth buds and young leaves. Uncured and unfermented.
Oolong tea: Made with partially fermented leaves. Oolong teas are full bodied in flavor and aroma.
Tea
 exerts benefits through polyphenols, commonly called catechins. The 
most potent catechin, EGCG, may help against free radicals that 
contribute to cancer, heart disease, and clogged arteries.
The 
more processed the leaves, usually the less polyphenol content. The 
processes used in black and oolong tea are known to decrease levels 
catechins more than other teas. Green tea contains the highest 
concentration of the powerful antioxidant EGCG.
Matcha green tea 
stone grinds the entire tea leaf, rather than infusing tea leaves in 
water. Matcha has EGCG concentrations 100 times more than a common green
 tea and 3 times more than other green teas.
Most of the nutrition
 in regular tea remains unused, trapped in the tea leaves. Matcha 
provides teas full arsenal of vitamins, minerals, and antioxidants. You 
need ~ten cups of regular tea to match the potency found in a single 
serving of matcha.
Herbal brews, like lavender, chamomile, and 
yerba mate are not technically considered tea. They are unique infusions
 of different plants with varying characteristics. Herbal teas have 
different concentrations of nutrients from green, white, black, and 
oolong tea.
Attention & Clarity
Tea consumption can 
improve mood and performance. A number of studies have shown 
particularly consistent evidence for improved attention, alertness, and 
arousal. Tea also shows beneficial effects on work performance and 
creativity.
Matcha green tea has been commonly used to aid 
clarity. Japanese monks would drink matcha to remain alert yet calm 
during long periods of meditation. Tea is rich in L-Theanine, an amino 
acid that promotes a state of relaxation and well-being.
Matcha 
contains more L-Theanine than common black and green teas. Additionally,
 L-Theanine can inhibit some of the side-effects from caffeine, a 
natural component of tea. The unique composition of green tea promotes 
concentration and clarity without the jitters or crash.
Cardiovascular & Other Disease
Tea
 consumption has been shown to protect against the development and 
progression of cardiovascular disease, one of the leading causes of 
mortality worldwide.
 The antioxidant, anti-inflammatory, 
antiproliferative, and endothelial function effects are thought to play a
 key role in these protective effects.
Although tea has been 
consumed for centuries, there are limited placebo controlled human 
studies as a health-promoting beverage. Further study is needed to 
clarify whether catechins represent ancillary ingredients or key 
molecules involved in the biological properties of green tea.
However,
 green tea represents a promising tool for the prevention of 
cardiovascular disorders, and an increase in the consumption of tea 
should be encouraged.
Weight Loss
Overall, green tea has a small positive effect on weight loss and weight management.
It
 affects thermogenesis by acting synergistically with the caffeine 
component. It can also augment other fat burning compounds, usually 
through COMT inhibition.
However, these effects may not work for 
everyone. The inconsistencies in fat oxidation may be due to individual 
differences, such as caffeine tolerance; the lower one's tolerance to 
caffeine is, the more effective green tea catechins appear to be on fat 
loss.
A recent meta-analysis found that each cup of green tea may be causative of burning 1/8 lb of body fat.