Green tea has many of the same benefits as water, which you can read about here: The benefits of water according to science. But, it also has many other benefits.
Many of the plant compounds found in the tea leaves make it into the final drink, these compounds contain many important nutrients.
There are large amounts of catechins, which are natural antioxidants that help prevent cell damage as well as providing other benefits.
EGCG (Epigallocatechin Gallate) is found in green tea, and has been found to treat a number of diseases.
Green tea, like all teas, contains caffeine; this is known to increase brain function. Where caffeine has been shown to increase conditions such as anxiety in some, the amino acid L-theanine is known to reduce it. Green tea contains large amounts of this important amino acid, which negates this potential downside of caffeine.
The combination of caffeine and L-theanine has been proven to have synergistic effects. The combination of the two being particularly potent at improving brain function.
Much like water, green tea is known to aid in fat reduction. It has the added benefit of the physical performance improvement gained by the caffeine.
So, if you are after a healthy drink that is not just plain old water. Give green tea a try.